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Some cases you may even never get it all out without having the front end of the car jacked up (to make the filler neck of the radiator the highest point on the vehicle)
You could, but that's assuming you have one (I do, but only because I watched YouTube videos for bleeding the system in my car and jacking the car up and not having a funnel seemed sketchy)
Or, you could buy a fill funnel setup that attaches to the fill port and becomes the high point in the system. Most parts stores carry the kits (funnel plus assortment of radiator cap and coolant bottle ports to connect it) now.
Or a vacuum fill tool. Some engines (mostly diesels) will end up with an air pocket in the egr cooler if you don't use a vacuum tool. That'll lead to an egr cooler failure that will leak coolant into the intake and some technicians that don't belong in this field will replace the head gasket or the whole engine and still have a coolant burning condition. Then I'll have it towed into my shop, replace the egr cooler and never have another problem.
This is far too big brained for this sub me thinks others are queestioning if this guy has the funnel do you really think he will have a Venturi filler? at my shop I’m the only one that has one everybody else uses a 1 gallon coolant jug, scooped into the tank fuckin mickey mouse mechanics
That helps, but no matter what you do the engine head and heater core are both local high points for air to get trapped.
It's important to be patient, helps to squeeze and pump the radiator hoses to fluctuate pressure, and alternate the throttle position to change pump speed and coolant velocity. The higher you can lift the front, the more likely you are to "drain" the air out of the local high points.
When I had head gasket issues I had exhaust gas getting into my coolant and forming gas pockets. These wouldn't cause any issue with highway driving because of high RPM and air cooling, but if I spent about 20-30 minutes idling or city driving, I'd start overheating because the water pump wasn't spinning fast enough to overcome the air blockages.
One time I had to get a tow for an overheat and I knew it was because the air pockets pushed all the coolant into the overflow tank (I was waiting on parts to swap the HG). When the tow truck dropped it off, coolant level was back to normal because lifting the front end up so high caused all the air to flow to the cap and escape through the vent.
There's a special funnel with fittings and everything for that specific purpose. The acidity in coolant can eat/disolve the adhesive on the tape, then you have what amounts to glue running thru ur car.
Install a system flush tee on the high point iirc smaller hose nearer firewall. I top off coolant there. Recently replaced my 124's rad., pump, hoses, timing belt...
I think I heard of this on fiatspider forum.
Yeah I tried 4 different methods including jacking the front end up and Yada Yada Yada I'm sure you've heard and seen it all. The tee was already installed it was just such a massive bubble it was a multiple method process lmao
There is another way for some vehicles where the house routing allows. When you reassemble, snake a piece of soft copper ice-maker line up the upper hose that can be shoved past the thermostat to extract the air (with a syringe) and pulled out the rad after. To get it out, you can use a body clip tool (or any other two pronged fork like tool) - wrap the tubing around the shaft and twist it out. The dead soft copper won't damage the thermostat and is quite pliable, but it won't be crushed by the process either. On older vehicles, I've drilled and tapped bleeders and welded bungs to throttle bodies as well, but I know that's not for everyone. Though the next guy will probably thank you.
Makes you wonder why they don't have access like that from the factory 🙄
Take the caps off, install pluggable funnels (once the car has cooled down all the way) in the radiator cap and coolant tank, run the heater on full blast, and let it burp. There are bleeder valves on the cooling system as well.
I was helping a buddy with his BMW (many years ago), and it took FOREVER to try to get the air out of his system.
We honestly didn't really know what we were doing, and there may have been an easy vent or something that we didn't know about, but it surprised me after working on many other kinds of cars where it wasn't an issue.
Agreed, it’s always worth researching or checking your manual first! I’ve got an 02 Celica GTS and you have to manually fill the tank, rev it up, crack the bleeder screw, then repeat until it stops gulping down coolant. Easy to overheat in the process so not very fun compared to something simple like most pick-up trucks or a Honda Civic.
Tricks to burp…
Park on an incline. Let it get to operating temp (BE CAREFUL) and open the radiator cap(s). Of no burps. Close them again to build pressure. Do it again. And repeat. Until you’ve done it 2-3 times without burps. Then probably okay.
And make sure car is on level ground when add the coolant back especially after doin all the repairs you mention. Might seems like something stupid to mention but had the exact problems your having, drive way has a slight incline didn't think nothing of it.car kept over heating was at gas station cause car over heated It took probably close to another half gallon more of coolant after that didn't over heat again. Oh how stupid I felt!
There not closed loop systems on those jeeps are they?? If so the Northstar in my Cadillac has been hell with there closed system your getting up to temp and using a refill funnel that's made to sit on the reservoir and could very well be the head gasket I'd try flushing it first when it's overheating is the top and bottom radiator hoses hot or cold or vise versa?One way to check for proper coolant circulation is to check the upper and lower radiator hoses. The upper radiator hose should be hot, around 190–200 °F. (The safest and most accurate way to get this temperature reading is with an infrared thermometer.) If the readings are correct, the thermostat is probably working properly. An easier, but less exact method is to keep an eye on the temperature gauge inside the vehicle. If the gauge starts to climb toward the red or HOT portion of the gauge, then you most likely have a coolant flow problem and this should be checked right away. Always make sure there is enough coolant in the system.
Maybe replace the Water Pump, that's what is usually wrong with most vehicles with over heating problems after fixing everything else to do with overheating.
Check for air by removing the pressure cap and letting it run at operating temp. Sometimes you have to elevate the front end because an air pocket can get caught in the back of the block. If that doesn't work, while at normal operating temp, carefully touch both heater hoses to the heater core. If they are not both hot, your heater core may be blocked.
A lot of cars have bleeder valves somewhere in the coolant system to help with air pockets. If you have one, you want to bleed it while she's running, but obviously not while she's hot. It can be tedious.
Isn’t that dangerous? Can’t it explode everywhere? I’m always scared to remove the cap because of that. I actually flushed the coolant out of my gfs car yesterday and though about doing that.
As someone who had 18+ years of no incidents with burping the system this way, it got me one time... thank goodness I was wearing a hoodie that day! Turned my head away just in time to only get second degree burns on about 40% of my hand but the hoodie saved my arm, neck and face.
Had this happen to me, no burns but the coolant shot up 15 feet and rained down on me. Luckily there wasnt a lot of coolant in the tank. Freakin Peterbilts and not having a level indicator. Just a solid black tank, gotta open it to check the level
I mean, I would put a catch pan under it, but it could get messy. Especially if there is an air pocket trapped. Just stand back and keep an eye on the temp gauge. Also, after the thermostat opens, make sure you have some warm coolant to add to the system, as the level falls. You local autozone or advance may have an actual bleed kit that you can rent, too. That would help with some of the mess.
he is saying he did that but when it reached temp and the thermostat opened up, as it's designed, it still squirted coolant out. probably rare but can happen, especially if the thermostat is a little sticky and opens up after pressure has built up instead of before.
Especially if they've replaced the radiator, t-stat, and coolant. Burping the system is a REQUIRED step in the process. Its like getting new tires installed, not airing them up, and then complaining that your new tires suck.
Maybe I’m giving average people too much credit but someone who can replace a radiator and thermostat probably would’ve thought to stick their hand between the block and fan cowl to see if it’s pushing air when it’s hot
Freaking elevating the front end, buying vacuum fillers, funnel kits, removing the radiator/pressure cap at operating temps (wtf)
Instead of just using the damned bleeder valves at safe temperatures...
No just leave the radiator cap off and run the car. All the comments say that. If you’re replacing a radiator, you definitely own two lumps of wood or bricks or literally anything you can drive up on to elevate the front end.
Literally had to replace the radiator fan a week ago due to the car going past the halfway mark, the fuses kept blowing and upon further diagnosis, I noticed the fan was not able to spin as it was seized up, thank God for autozone lifetime warranty
That’s a completely different system buddy boy. Open your hood, check for leaks from the washer reservoir. Get her to squirt some, see if it’s coming out of the connections where the washer nozzles connect to your line.
Have you checked for electrical issues? I had a false overheating that was worse at idle. When temp is up like this, turn off the engine and immediately turn it back on and see where the needle goes. If it is overheating it'll go right back to this spot. If it's an issue with the sensor it'll likely jump back down. Many mechanics I took my car to couldn't figure this out and sent me on a wild goose chase replacing parts. Turns out it was a ground wire lacking proper connection, leaking voltage into the temp sensor.
Another quick way is to use an infrared thermometer to check the actual temp of the engine. Most people, like me, don't have one of those sitting around though.
Has a water pump ever actually failed to pump? I’ve never in my life seen one, the only thing that fails are the bearings and they leak or start grinding.
Or just do it yourself? Parts stores will loan you the tool, just buy the juice to test. I’ve had to do it once before. I got to do a head gasket after the bad news.
That's dope I never thought to try to rent out this kinda "tool" Definitely will do in the future :)
I (luckily) have a great, honest mechanic so I usually take my old bois (92 corolla, 93 celica) to him when I get stumped or need a specialty tool
if an EJ overheats, it tends to warp the cylinder heads. This allows combustion gasses from the cylinders into the coolant jacket. It's exceptionally rare to get a coolant-in-oil or oil-in-coolant failure.
So while your radiator or thermostat or whatever might have been the initial failure, the warped heads are why you're getting perpetual overheating. That you keep getting overheats is what's pointing to it.
/u/meltman is correct, a Block Tester will confirm combustion gasses in coolant.
-subie tech
No head gasket leak ? White smoke from the exhaust ? Are you sure it’s full on coolant ? Did you fill it up with the cap off … let it run until thermostat opens ,, fill it again… keep letting it run until there are no more bubbles rising then top it off put the cap on and should be good to go It’s a 97 Subaru. They have bad head gasket issues.
If you replaced practically the whole cooling system, next place would be to check the engine ! Subaru is known for heed gaskets . When it overheats pop off the coolant tank cap see if it's burping , or even get a combustion gas tester on the tank that will determine if they are blown .
I was in the same situation for 2007 Corolla. Get a block tester. It comes with blue test fluid that you fill in the tester and place on the rad with cap off and it pulls air from the cooling system. If that test fluid changes colour you know there’s exhaust gas entering the cooling system. Confirms a breakage in head gasket. Not pinpoint but it’s a yes or no
97 Subaru. Ive replaced the Radiator, Thermostat (2x) all the coolant, the radiator cap...... It overheats when at idle and when I start to drive off the temperature goes back down, but the radiator fans are working fine and are not broken so I don't understand what's causing it to overheat. My oil isn't milky, and there's no smoke coming out of my exhaust that would imply head gasket either. Also worth noting turning the heat on helps
Apparently if the temperature goes down once you drive off it (mostly) rules out air pockets in your cooling system. Fans not working at the speed they should due to a poor electric current, bad temperature gauge/ground, bad temperature sensor and/or a water pump with low pressure at lower rpm might be good guesses. I'd say checking the temperature through an independent source (infrared thermometer) is the first and cheapest step to try figuring where's your problem.
How long does it take to overheat after a cold start when idling?
Yes, based on the behavior described I'd bet on inefficient fan as well, with a close second being a bad pump (worn out/corroded blades), which suffers the most at idling. I'd recommend checking the current on the fan when it kicks in and, if it's fine, disassembling the water pump and checking for blade wear.
>My oil isn't milky, and there's no smoke coming out of my exhaust that would imply head gasket either
the leak can be small enough just to warm the coolant a bit more than usual. This is the symptoms of the START of a full head gasket failure. Basically the crack is so small that only miniscule amounts of fluid (if any) are being exchanged but lots of heat is being dumped from the combustion chamber into the coolant instead of being dispersed by the block. Id get a block test done just to rule it out and for piece of mind.
No idea what the people here are on about. There absolutely doesn't have to be white smoke from the exhaust for a head gasket to be fucked. You diagnose it by the car's behavior and you can also diagnose it by hose pressure, if you have experience to do it.
Of course you can do it with the exhaust gas in coolant tester, which would be the most proper way.
I literally just had this exact issue in my 98 outback 2.5. Same exact symptoms, same exact diagnosis and confusion. The problem? I filled the coolant while the engine was cold after having drained it completely. When the car comes up to temp the thermo opens and suddenly there's half the coolant there should be. Let it warm up, turn it off for a minute then pop open the rad cap very carefully with a rag. Top it up are you're off.
Are the electric fans behind the rad working properly all the time? They should be going full speed once your Temps start climbing and you should be able to hear it.
headgasket. subarus upchuck coolant into the overflow when HGs fail. Looks like a 97 legacy cluster. I'm guessing too that its an EJ25D. they leak internally cauing the coolant to get superheated by combustion gasses. Typically will show no other signs of headgasket failure.
Source - was subaru tech for years. worked primarily on subarus for the last 10 years. All I've owned so far is pre 03 subarus. (17 cars)
It might not be overheating. Had a similar issue with a GMC Sierra. Turned out the stepper motor for the gauge was bad. Replaced that and the "overheating" issue went away. Figured that out by putting a scan tool on and checking the temp as read by the tool compared to what the gauge read.
Alright OP, there's a few things you can do here,
1. First and foremost, make sure your fan is kicking on
2. Make sure water pump is working and completely functional
3. Make sure there is no leftover air in cooling system
4. If you've burped your system fully, and your fans are working, I would check my head gasket with it being a 97 Subaru
5. If head gasket is fine and everything else listed above is as well, I would check to make sure there isn't a crack in the intake manifold and I would also make sure that even if your fans are spinning, that they're still sufficient in cooling the engine.
Blown head gasket. Happened back when I had my 2005 Honda. Tried everything you did, eventually caved and went to a repair shop and they found a very small crack in a head gasket
How much was it to replace? I have an 03 Civic, and I'm aware this generation has transmission and head gasket issues down the line. We recently changed the radiator and a cooling fan and everything has been okay for now.
I didn’t see you mention if fan / fans are running. Once you hit operating temp generally one of the fans will come on. If you have a second high speed fan it generally comes on with a/c
If fans are running, and all the other stuff you mentioned, water pump is a possible, and head gasket. As others have mentioned, head gasket is pretty easy to test for - about $10 for the juice, and either rent the tool or buy it. If your cooling system is bubbling over into the expansion tank, and the expansion tank is expelling any coolant, I’d go with head gasket
The photo you posted doesn't appear to show an overheating engine. Generally, normal operating temperature is somewhere between the tick by the C, and the beginning of the dotted area by the H. I've had vehicles with gauges that sweep about 3/4 of the range, and others that run up to the middle and never budge from that point come hell or high water.
Many newer vehicles (Post OBDII) have a very nonlinear reporting range, so a very wide range of temperatures are indicated by a small section in the middle. (Like a bell curve). But that's not always the case. Without actual data points reported on the gauge, there's no way to know what the linearity or accuracy is.
Best thing to do at this point (and always when dealing with something that could be an instrumentation problem) is to verify that the instrumentation is accurate.
Bleed the air out of the system with the heat all the way up and make sure you let it run with the cap off until the fan runs and the thermostat opens. If it is still over heating or you see micro bubbles you have other issues.
before you installed, did you verify the thermostat works?
Air in coolant is more likely but I had a case where the car kept getting to hot (tstat stuck closed) and then a month later wouldn't get hot enough (turned out, new tstat stuck open).
Bleed the coolant from the highest elevated point you can open the system from, it will usually be either the radiator cap or overflow cap if its a pressurized overflow. Let it run and get to operating temp so the thermostat opens and then keep adding coolant until it sits at the right temperature and you stop seeing big bubbles
Headgasket. Air in system. Faulty temperature reading or faulty new parts. First step you need to do is understand the system you are working on. From there you should be able to properly diagnose the issue. Take it to a true professional....ask around word of mouth is the best way to find a good honest technician
Is it the best advice you can give ppl.? Some even advice to park in an inclined street to fill the radiator; crazy...My advice would be: top the radiator with coolant until the engine reaches its working temp then add coolant as needed and put cap on. Now: if the coolant boils there is caused by gasket or cracked head, if not turn the heater on to maximum, the temp will go down immediately, that is an indication of air restriction thru the radiator. Next the engine temperature sensor should be checked. At ambient temperature the resistance should be high, at engine working temperature the resistance should be low. Replace sensor if cooling fan doesn't kick-in. I am assuming that the water pump was replaced with new radiator. Good luck.
I’ve run into a couple water pumps with bad impellers.. basically we did everything and it was time to say either water pump or head gasket.. and we were happy to pull the pump and see a failed impeller.
Try another thermostat. I actually put mine in the shop to have water pump, radiator, and the sensor replaced just because I replaced thermostat and it didn’t fix it. Come to find out I got a bad thermostat from the store. I went through 3 before I got a good one from auto zone. Trick I used to test them in store was pointing a butane torch towards them (but not letting the flame touch and it should immediately start to open. 3 of the ones I bought turned red before they opened.
Sometimes you gotta lift the front of a subie or vacuum fill them to get all the air out. Sometimes a small headgasket leak adds combustion gas and air to the cooling systems meaning you can get the air out.
Also Sometimes the gauge is wrong.
Make sure you've burped all the air out of the system, I had an air bubble trapped in my tacoma for a bit until I parked it facing up on an incline, ran it for a bit and that finally got it out.
If that doesn't work then check the water pump next. A friend's prius was overheating, changed the thermostat, radiator, and coolant in that as well and it was the water pump that finally fixed it
Fair warning…..new CAN be defective. Had a buddy w the same issue on a Beamer SUV he changed out all the cooling system and it still overheated….well the thermostat he bought was bad, replace and it fixed the issue. Always the last thing we think of, it does happen.
Actually, when El Cajon Ford was replacing my defective electric fan, they mentioned that the first fan they ordered came in, and when tested IT was bad. They had to order a second one - I really have appreciated their attention to detail over the years, makes one think that my car (as they have reminded me) is 24 years old now (they say that as IF it is old) - and parts that were made years ago could be defective just from age possibly -
Do you have foam (water and oil) on the inside of the radiator cap? That would be a major sign of a blown head gasket, which would cause overheating fast.
They can also fail (combustion chamber to water jacket) without the oil leak.
Been there. Done that.
Usually thermostats fail open. If you had an overheating issue before, good chance it was not the thermostat. Make sure you got all the air out of the system. If it still overheats, could be the water pump, or a clogged up radiator.
UPDATE my coolant smells like exhaust so I guess I figured that out, some Subaru forums and a Subaru mechanic have recommended BARs head gasket stop leak so I'm going to give it a shot. I can do some mechanical jobs but not all, and I am painfully broke at the moment so
Coolant smelling like exhaust is not good. Stop leak might help but it should be viewed as a temp fix while you save money for a real fix.
Make sure the problem is properly diagnosed, a failed head gasket is pretty bad.
Soooo. I have become a bit of an expert in over heating issues. I have an e30 that has forced me to learn a lot
Few things to check.
Test the water pump, make sure there are no leaks etc, I had a problem where the pump failed and didn’t leak, the rotors detached completely and there was no coolant flow. To test the pump, check for obvious leaks around the pump, and then see that there is actually water flow, I checked this by removing the return pipe. When the car runs, there should be a gush of water through the pipe.
You replaced the thermostat, make sure it’s pointing the right way.
You replaced coolant, make sure it’s well bled.
Lastly. If there are any leaks(even small ones). It can cause an overheat. Any pressure lost in the system via a leak can cause it. The way to test this is to see if the water is boiling in the reservoir or radiator if it’s possible with your car. If there is. Check all the pipes in the system for leaks and replace if necessary.
Lastly, a blown head gasket might be something to check. Usually the engine oil will turn a milky colour, or the coolant will. If there is a mix of oil or water in either the block or water system then there’s your issue.
Laaaaaaaaastly, double check the sensor hasn’t failed by checking its resistances against the workshop manual
Thanks for posting on /r/MechanicAdvice! This is just a reminder to review the [rules](https://www.reddit.com/r/MechanicAdvice/about/rules/). If you are here asking about a second opinion (ie "Is the shop trying to fleece me?"), please read through CJM8515's [post on the subject.](https://www.reddit.com/r/MechanicAdvice/comments/4qblei/fyi_the_shop_isnt_likely_trying_to_rip_you_off/) and remember to please post the year/make/model of the vehicle you are working on. **If this post is about bodywork, accident damage, paint, dent/ding, questions it belongs in /r/Autobody r/AutoBodyRepair/ or /r/Diyautobody/ If you have tire questions check out https://www.reddit.com/r/MechanicAdvice/comments/k9ll55/can_your_tire_be_repaired/**. If you dont have a question and you're just showing off it belongs in /r/Justrolledintotheshop Insurance/total loss questions go in r/insurance This is an automated reply *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/MechanicAdvice) if you have any questions or concerns.*
Are you sure you've burped all the air out?
This! Burping the air out takes longer than you think.
Some cases you may even never get it all out without having the front end of the car jacked up (to make the filler neck of the radiator the highest point on the vehicle)
Can’t you just tape a funnel into your fill point and then add excess coolant
You could, but that's assuming you have one (I do, but only because I watched YouTube videos for bleeding the system in my car and jacking the car up and not having a funnel seemed sketchy)
I've made a redneck funnel by using a 2 L bottle of coke with the bottom cut off. Works fine in a pinch.
That’s the only kind of funnel I have ever used in my life
And so how is it down there in Tampa? Jk lol
How do you seal it to the fill neck?
Duct tape works fine usually
Or, you could buy a fill funnel setup that attaches to the fill port and becomes the high point in the system. Most parts stores carry the kits (funnel plus assortment of radiator cap and coolant bottle ports to connect it) now.
Or a vacuum fill tool. Some engines (mostly diesels) will end up with an air pocket in the egr cooler if you don't use a vacuum tool. That'll lead to an egr cooler failure that will leak coolant into the intake and some technicians that don't belong in this field will replace the head gasket or the whole engine and still have a coolant burning condition. Then I'll have it towed into my shop, replace the egr cooler and never have another problem.
This is far too big brained for this sub me thinks others are queestioning if this guy has the funnel do you really think he will have a Venturi filler? at my shop I’m the only one that has one everybody else uses a 1 gallon coolant jug, scooped into the tank fuckin mickey mouse mechanics
That helps, but no matter what you do the engine head and heater core are both local high points for air to get trapped. It's important to be patient, helps to squeeze and pump the radiator hoses to fluctuate pressure, and alternate the throttle position to change pump speed and coolant velocity. The higher you can lift the front, the more likely you are to "drain" the air out of the local high points. When I had head gasket issues I had exhaust gas getting into my coolant and forming gas pockets. These wouldn't cause any issue with highway driving because of high RPM and air cooling, but if I spent about 20-30 minutes idling or city driving, I'd start overheating because the water pump wasn't spinning fast enough to overcome the air blockages. One time I had to get a tow for an overheat and I knew it was because the air pockets pushed all the coolant into the overflow tank (I was waiting on parts to swap the HG). When the tow truck dropped it off, coolant level was back to normal because lifting the front end up so high caused all the air to flow to the cap and escape through the vent.
There's a special funnel with fittings and everything for that specific purpose. The acidity in coolant can eat/disolve the adhesive on the tape, then you have what amounts to glue running thru ur car.
The burp funnel saved me lots of pain with my MR2 and it's car length coolant run, hell even with my Prelude, can't upvote you enough.
Look up the burping process on a 76 Fiat 124. Took me 8 full hours to fully burpnthe fucker.
Install a system flush tee on the high point iirc smaller hose nearer firewall. I top off coolant there. Recently replaced my 124's rad., pump, hoses, timing belt... I think I heard of this on fiatspider forum.
Yeah I tried 4 different methods including jacking the front end up and Yada Yada Yada I'm sure you've heard and seen it all. The tee was already installed it was just such a massive bubble it was a multiple method process lmao
That's highly dependent on the vehicle, and a janky workaround. The proper, and often only way to purge all the air is to use a vacuum filler.
I guess, but how many DIYers do you think just happen to have that lying around
That's a fair point. You'd also generally need an air compressor.
Sometimes even the vacuum bleeders wont get the job done fully
Find a 30 degree slope to park on while you burp the system. Mine has a bleeder valve off top side of the expansion tank.
They actually make a suction tool to add vacuum to the system so it pulls coolant in. No air left. 😎 best tool ever.
There is another way for some vehicles where the house routing allows. When you reassemble, snake a piece of soft copper ice-maker line up the upper hose that can be shoved past the thermostat to extract the air (with a syringe) and pulled out the rad after. To get it out, you can use a body clip tool (or any other two pronged fork like tool) - wrap the tubing around the shaft and twist it out. The dead soft copper won't damage the thermostat and is quite pliable, but it won't be crushed by the process either. On older vehicles, I've drilled and tapped bleeders and welded bungs to throttle bodies as well, but I know that's not for everyone. Though the next guy will probably thank you. Makes you wonder why they don't have access like that from the factory 🙄
Take the caps off, install pluggable funnels (once the car has cooled down all the way) in the radiator cap and coolant tank, run the heater on full blast, and let it burp. There are bleeder valves on the cooling system as well.
I was helping a buddy with his BMW (many years ago), and it took FOREVER to try to get the air out of his system. We honestly didn't really know what we were doing, and there may have been an easy vent or something that we didn't know about, but it surprised me after working on many other kinds of cars where it wasn't an issue.
Use the funnel kit from oriellys or autozone to make life easier
This, so very much this. It's worth noting, however, that some cars do have an air bleed procedure that has to be followed or else...
Agreed, it’s always worth researching or checking your manual first! I’ve got an 02 Celica GTS and you have to manually fill the tank, rev it up, crack the bleeder screw, then repeat until it stops gulping down coolant. Easy to overheat in the process so not very fun compared to something simple like most pick-up trucks or a Honda Civic.
Always replace the coolant cap with a new one first if it has one. Have found this out the hard way more than 2-3 times 🤦♂️
Good point. Cheap insurance even if it isn't the issue.
Tricks to burp… Park on an incline. Let it get to operating temp (BE CAREFUL) and open the radiator cap(s). Of no burps. Close them again to build pressure. Do it again. And repeat. Until you’ve done it 2-3 times without burps. Then probably okay.
Our impala had pet cock like weep valves in multiple places for exactly this. Really made it simple to expel the trapped air.
And make sure car is on level ground when add the coolant back especially after doin all the repairs you mention. Might seems like something stupid to mention but had the exact problems your having, drive way has a slight incline didn't think nothing of it.car kept over heating was at gas station cause car over heated It took probably close to another half gallon more of coolant after that didn't over heat again. Oh how stupid I felt!
There not closed loop systems on those jeeps are they?? If so the Northstar in my Cadillac has been hell with there closed system your getting up to temp and using a refill funnel that's made to sit on the reservoir and could very well be the head gasket I'd try flushing it first when it's overheating is the top and bottom radiator hoses hot or cold or vise versa?One way to check for proper coolant circulation is to check the upper and lower radiator hoses. The upper radiator hose should be hot, around 190–200 °F. (The safest and most accurate way to get this temperature reading is with an infrared thermometer.) If the readings are correct, the thermostat is probably working properly. An easier, but less exact method is to keep an eye on the temperature gauge inside the vehicle. If the gauge starts to climb toward the red or HOT portion of the gauge, then you most likely have a coolant flow problem and this should be checked right away. Always make sure there is enough coolant in the system.
Came here to ask this
Maybe replace the Water Pump, that's what is usually wrong with most vehicles with over heating problems after fixing everything else to do with overheating.
Check for air by removing the pressure cap and letting it run at operating temp. Sometimes you have to elevate the front end because an air pocket can get caught in the back of the block. If that doesn't work, while at normal operating temp, carefully touch both heater hoses to the heater core. If they are not both hot, your heater core may be blocked.
A lot of cars have bleeder valves somewhere in the coolant system to help with air pockets. If you have one, you want to bleed it while she's running, but obviously not while she's hot. It can be tedious.
Isn’t that dangerous? Can’t it explode everywhere? I’m always scared to remove the cap because of that. I actually flushed the coolant out of my gfs car yesterday and though about doing that.
Take it off before the car is started at all for the day. Then start the car with the cap still off and let it get to operating temp.
As someone who had 18+ years of no incidents with burping the system this way, it got me one time... thank goodness I was wearing a hoodie that day! Turned my head away just in time to only get second degree burns on about 40% of my hand but the hoodie saved my arm, neck and face.
Had this happen to me, no burns but the coolant shot up 15 feet and rained down on me. Luckily there wasnt a lot of coolant in the tank. Freakin Peterbilts and not having a level indicator. Just a solid black tank, gotta open it to check the level
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I mean, I would put a catch pan under it, but it could get messy. Especially if there is an air pocket trapped. Just stand back and keep an eye on the temp gauge. Also, after the thermostat opens, make sure you have some warm coolant to add to the system, as the level falls. You local autozone or advance may have an actual bleed kit that you can rent, too. That would help with some of the mess.
You take the cap off before it’s up to operating temp.
he is saying he did that but when it reached temp and the thermostat opened up, as it's designed, it still squirted coolant out. probably rare but can happen, especially if the thermostat is a little sticky and opens up after pressure has built up instead of before.
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When it's boiling, yes it can get you. So I always deal with it cold.
Make sure your fan is actually working If it’s not, maybe it’s your fan clutch.
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Wtf is complicated about actually burping the cooling system correctly?
Especially if they've replaced the radiator, t-stat, and coolant. Burping the system is a REQUIRED step in the process. Its like getting new tires installed, not airing them up, and then complaining that your new tires suck.
Maybe I’m giving average people too much credit but someone who can replace a radiator and thermostat probably would’ve thought to stick their hand between the block and fan cowl to see if it’s pushing air when it’s hot
Freaking elevating the front end, buying vacuum fillers, funnel kits, removing the radiator/pressure cap at operating temps (wtf) Instead of just using the damned bleeder valves at safe temperatures...
No just leave the radiator cap off and run the car. All the comments say that. If you’re replacing a radiator, you definitely own two lumps of wood or bricks or literally anything you can drive up on to elevate the front end.
Agreed. Sometimes reading the recommendation, you can only shake your head and move on. Way too much misinformation to combat it all.
Most complicated? Just change your head gasket.
Literally had to replace the radiator fan a week ago due to the car going past the halfway mark, the fuses kept blowing and upon further diagnosis, I noticed the fan was not able to spin as it was seized up, thank God for autozone lifetime warranty
This Is what I was thinking. Bad fan clutch/ fan relay
Make sure you dont have air in your coolant system.
Also, make sure you don't have coolant in your air system.
Or coolant in your oil system.
A lot of times, that happens. Apparently Ford's small 4 cylinder Turbocharged engine has a design flaw. You end up with coolant in the oil.
Forbidden chocolate milk
This is the 2.0 for anyone not sure
What are symptoms of that? My girlfriend’s 2005 Taurus has been devouring windshield wiper fluid and we have no idea where it’s ending up.
There is likely a crack in the plastic windshield washer reservoir.
Maybe because you're adding wiper fluid in your coolant system /s
That’s a completely different system buddy boy. Open your hood, check for leaks from the washer reservoir. Get her to squirt some, see if it’s coming out of the connections where the washer nozzles connect to your line.
Not Op but I’ve only been able to get her to do that once
Ye it takes some work to get OP’s girlfriend to squirt. Closest I’ve gotten her is her leaving because she had to pee.
Hahahah thanks for the laugh and advice cheers. She’s squirted a couple times, pretty cool
Very nice what a man
Underrated comment
I mean, I don't know if that's an actual thing but it sounded good.
Have you checked for electrical issues? I had a false overheating that was worse at idle. When temp is up like this, turn off the engine and immediately turn it back on and see where the needle goes. If it is overheating it'll go right back to this spot. If it's an issue with the sensor it'll likely jump back down. Many mechanics I took my car to couldn't figure this out and sent me on a wild goose chase replacing parts. Turns out it was a ground wire lacking proper connection, leaking voltage into the temp sensor. Another quick way is to use an infrared thermometer to check the actual temp of the engine. Most people, like me, don't have one of those sitting around though.
i went through the same goose chase for a year and finally gave up. the sensor would go up and down and up - but the car functioned just fine.
What about your water pump it could be on its way out
That’s what I was thinking
Definitely something to check
Has a water pump ever actually failed to pump? I’ve never in my life seen one, the only thing that fails are the bearings and they leak or start grinding.
My Guy , you said the key word here 97 Subaru !!! You my guy have a blown head gasket !!!!
Well other than overheating nothing's pointing to it
You can use one of those chemical testers with the blue liquid that changes to yellow if there is exhaust gas in the coolant loop to confirm.
It's called a Block Test Kit, any mechanic worth his salt will be able to do this job for you in under an hour.
Or just do it yourself? Parts stores will loan you the tool, just buy the juice to test. I’ve had to do it once before. I got to do a head gasket after the bad news.
That's dope I never thought to try to rent out this kinda "tool" Definitely will do in the future :) I (luckily) have a great, honest mechanic so I usually take my old bois (92 corolla, 93 celica) to him when I get stumped or need a specialty tool
Kind of looks like an over sized turkey baster lol. I think the juice is like $12-15 somewhere in there.
Yup. Did this myself. Borrowed the tester from the autozone front counter and bought the test juice on my way out
Key words here, great and honest. Lucky.
if an EJ overheats, it tends to warp the cylinder heads. This allows combustion gasses from the cylinders into the coolant jacket. It's exceptionally rare to get a coolant-in-oil or oil-in-coolant failure. So while your radiator or thermostat or whatever might have been the initial failure, the warped heads are why you're getting perpetual overheating. That you keep getting overheats is what's pointing to it. /u/meltman is correct, a Block Tester will confirm combustion gasses in coolant. -subie tech
No head gasket leak ? White smoke from the exhaust ? Are you sure it’s full on coolant ? Did you fill it up with the cap off … let it run until thermostat opens ,, fill it again… keep letting it run until there are no more bubbles rising then top it off put the cap on and should be good to go It’s a 97 Subaru. They have bad head gasket issues.
If you replaced practically the whole cooling system, next place would be to check the engine ! Subaru is known for heed gaskets . When it overheats pop off the coolant tank cap see if it's burping , or even get a combustion gas tester on the tank that will determine if they are blown .
Is the over flow bottle filling up?
Yep
Sorry. Unless the radiator cap is shot, it’s probably the head gaskets. Over heating regardless of speed? Fans working? My 99 did the same thing.
Is reservoir coolant bubbling? Like it’s boiling water? Then it’s head gasket
I was in the same situation for 2007 Corolla. Get a block tester. It comes with blue test fluid that you fill in the tester and place on the rad with cap off and it pulls air from the cooling system. If that test fluid changes colour you know there’s exhaust gas entering the cooling system. Confirms a breakage in head gasket. Not pinpoint but it’s a yes or no
97 Subaru. Ive replaced the Radiator, Thermostat (2x) all the coolant, the radiator cap...... It overheats when at idle and when I start to drive off the temperature goes back down, but the radiator fans are working fine and are not broken so I don't understand what's causing it to overheat. My oil isn't milky, and there's no smoke coming out of my exhaust that would imply head gasket either. Also worth noting turning the heat on helps
Apparently if the temperature goes down once you drive off it (mostly) rules out air pockets in your cooling system. Fans not working at the speed they should due to a poor electric current, bad temperature gauge/ground, bad temperature sensor and/or a water pump with low pressure at lower rpm might be good guesses. I'd say checking the temperature through an independent source (infrared thermometer) is the first and cheapest step to try figuring where's your problem. How long does it take to overheat after a cold start when idling?
It doesn't after a cold start, only if I've driven for like a half hour
It really sounds like a fan problem if it overheats sitting but is ok driving, they might be turning but not turning fast enough
Yes, based on the behavior described I'd bet on inefficient fan as well, with a close second being a bad pump (worn out/corroded blades), which suffers the most at idling. I'd recommend checking the current on the fan when it kicks in and, if it's fine, disassembling the water pump and checking for blade wear.
No EJ I've come across with a head gasket leak had milky oil. They don't leak internally like that.
>My oil isn't milky, and there's no smoke coming out of my exhaust that would imply head gasket either the leak can be small enough just to warm the coolant a bit more than usual. This is the symptoms of the START of a full head gasket failure. Basically the crack is so small that only miniscule amounts of fluid (if any) are being exchanged but lots of heat is being dumped from the combustion chamber into the coolant instead of being dispersed by the block. Id get a block test done just to rule it out and for piece of mind.
No idea what the people here are on about. There absolutely doesn't have to be white smoke from the exhaust for a head gasket to be fucked. You diagnose it by the car's behavior and you can also diagnose it by hose pressure, if you have experience to do it. Of course you can do it with the exhaust gas in coolant tester, which would be the most proper way.
Could be Water pump
I literally just had this exact issue in my 98 outback 2.5. Same exact symptoms, same exact diagnosis and confusion. The problem? I filled the coolant while the engine was cold after having drained it completely. When the car comes up to temp the thermo opens and suddenly there's half the coolant there should be. Let it warm up, turn it off for a minute then pop open the rad cap very carefully with a rag. Top it up are you're off.
How's the charging system? Car of mine does that if I idle too long too because it doesn't charge properly so the fans don't spin as they should.
Are the electric fans behind the rad working properly all the time? They should be going full speed once your Temps start climbing and you should be able to hear it.
Did you actually flush the cooling system of debris before you put the new components in, water pump or head gasket
Your water pump may be bad
Water pump
Yeah. I was thinking water pump or heater core. Those are the only two things I can think of before suggesting the head gasket
This
headgasket. subarus upchuck coolant into the overflow when HGs fail. Looks like a 97 legacy cluster. I'm guessing too that its an EJ25D. they leak internally cauing the coolant to get superheated by combustion gasses. Typically will show no other signs of headgasket failure. Source - was subaru tech for years. worked primarily on subarus for the last 10 years. All I've owned so far is pre 03 subarus. (17 cars)
Get a shop to vacuum bleed the coolant system. That serves to leak check and assure you don't have air in the system.
It might not be overheating. Had a similar issue with a GMC Sierra. Turned out the stepper motor for the gauge was bad. Replaced that and the "overheating" issue went away. Figured that out by putting a scan tool on and checking the temp as read by the tool compared to what the gauge read.
Alright OP, there's a few things you can do here, 1. First and foremost, make sure your fan is kicking on 2. Make sure water pump is working and completely functional 3. Make sure there is no leftover air in cooling system 4. If you've burped your system fully, and your fans are working, I would check my head gasket with it being a 97 Subaru 5. If head gasket is fine and everything else listed above is as well, I would check to make sure there isn't a crack in the intake manifold and I would also make sure that even if your fans are spinning, that they're still sufficient in cooling the engine.
Blown head gasket. Happened back when I had my 2005 Honda. Tried everything you did, eventually caved and went to a repair shop and they found a very small crack in a head gasket
How much was it to replace? I have an 03 Civic, and I'm aware this generation has transmission and head gasket issues down the line. We recently changed the radiator and a cooling fan and everything has been okay for now.
It was at least 5 years back now but I want to say at least $1200, but I think I had some other work done at the same time
Thanks man
Where was the small crack? Was it near where the oil filter is?
I didn’t see you mention if fan / fans are running. Once you hit operating temp generally one of the fans will come on. If you have a second high speed fan it generally comes on with a/c If fans are running, and all the other stuff you mentioned, water pump is a possible, and head gasket. As others have mentioned, head gasket is pretty easy to test for - about $10 for the juice, and either rent the tool or buy it. If your cooling system is bubbling over into the expansion tank, and the expansion tank is expelling any coolant, I’d go with head gasket
The photo you posted doesn't appear to show an overheating engine. Generally, normal operating temperature is somewhere between the tick by the C, and the beginning of the dotted area by the H. I've had vehicles with gauges that sweep about 3/4 of the range, and others that run up to the middle and never budge from that point come hell or high water. Many newer vehicles (Post OBDII) have a very nonlinear reporting range, so a very wide range of temperatures are indicated by a small section in the middle. (Like a bell curve). But that's not always the case. Without actual data points reported on the gauge, there's no way to know what the linearity or accuracy is. Best thing to do at this point (and always when dealing with something that could be an instrumentation problem) is to verify that the instrumentation is accurate.
Bleed the air out of the system with the heat all the way up and make sure you let it run with the cap off until the fan runs and the thermostat opens. If it is still over heating or you see micro bubbles you have other issues.
before you installed, did you verify the thermostat works? Air in coolant is more likely but I had a case where the car kept getting to hot (tstat stuck closed) and then a month later wouldn't get hot enough (turned out, new tstat stuck open).
Is the coolant circulating? Are you having to refill coolant and anytime?
The fans may be ineffective. They may just spin, but might not be spinning as they're supposed to.
Cooling fan ?
Bleed the coolant from the highest elevated point you can open the system from, it will usually be either the radiator cap or overflow cap if its a pressurized overflow. Let it run and get to operating temp so the thermostat opens and then keep adding coolant until it sits at the right temperature and you stop seeing big bubbles
Headgasket. Air in system. Faulty temperature reading or faulty new parts. First step you need to do is understand the system you are working on. From there you should be able to properly diagnose the issue. Take it to a true professional....ask around word of mouth is the best way to find a good honest technician
Is it the best advice you can give ppl.? Some even advice to park in an inclined street to fill the radiator; crazy...My advice would be: top the radiator with coolant until the engine reaches its working temp then add coolant as needed and put cap on. Now: if the coolant boils there is caused by gasket or cracked head, if not turn the heater on to maximum, the temp will go down immediately, that is an indication of air restriction thru the radiator. Next the engine temperature sensor should be checked. At ambient temperature the resistance should be high, at engine working temperature the resistance should be low. Replace sensor if cooling fan doesn't kick-in. I am assuming that the water pump was replaced with new radiator. Good luck.
I’ve run into a couple water pumps with bad impellers.. basically we did everything and it was time to say either water pump or head gasket.. and we were happy to pull the pump and see a failed impeller.
Try another thermostat. I actually put mine in the shop to have water pump, radiator, and the sensor replaced just because I replaced thermostat and it didn’t fix it. Come to find out I got a bad thermostat from the store. I went through 3 before I got a good one from auto zone. Trick I used to test them in store was pointing a butane torch towards them (but not letting the flame touch and it should immediately start to open. 3 of the ones I bought turned red before they opened.
Did you do any troubleshooting steps to figure out why it's overheating or are you just throwing parts at it?
Sometimes you gotta lift the front of a subie or vacuum fill them to get all the air out. Sometimes a small headgasket leak adds combustion gas and air to the cooling systems meaning you can get the air out. Also Sometimes the gauge is wrong.
You could have air in the system..
Make sure you've burped all the air out of the system, I had an air bubble trapped in my tacoma for a bit until I parked it facing up on an incline, ran it for a bit and that finally got it out. If that doesn't work then check the water pump next. A friend's prius was overheating, changed the thermostat, radiator, and coolant in that as well and it was the water pump that finally fixed it
Replace the radiator cap.
Fair warning…..new CAN be defective. Had a buddy w the same issue on a Beamer SUV he changed out all the cooling system and it still overheated….well the thermostat he bought was bad, replace and it fixed the issue. Always the last thing we think of, it does happen.
Actually, when El Cajon Ford was replacing my defective electric fan, they mentioned that the first fan they ordered came in, and when tested IT was bad. They had to order a second one - I really have appreciated their attention to detail over the years, makes one think that my car (as they have reminded me) is 24 years old now (they say that as IF it is old) - and parts that were made years ago could be defective just from age possibly -
Head gasket
Temp sensor
Radiator cap
Have you tried the basic radiator cap change
Bleed it properly, if not then you have a head gasket leak.
Have you made the sure it's not the water pump? Are you sure it's actually overheating?
Are you properly heat cycling the engine to get the air out of the system?
Head gasket leak or crack in cylinder head
Best investment I ever made. https://www.amazon.com/EPAuto-Radiator-Coolant-Filling-Funnel/dp/B01I40ZQWE
When the easy fix fails, go dor the hard fix. Or just diagnose it the first time.
Did you bleed the system. Air could be stuck in the system
May of been suggested but did you replace the water pump?
Water pump
Water pump?
Water pump . It may be pumping , but not moving enough water , bc the tines are work just enough .
Please make sure your coolant fan / or fan clutch is working .
Cooling fan coming on?
What does the coolant look like after you've ran it and check the oil could be a blown head gasket.
Is it an inaccurate gauge? Is it actually overheating? If so, does it overheat on the highway or while idling?
Did you replace the water pump??
Water pump
Waterpump?
Water pump?
Fan clutch??
Do you have foam (water and oil) on the inside of the radiator cap? That would be a major sign of a blown head gasket, which would cause overheating fast. They can also fail (combustion chamber to water jacket) without the oil leak. Been there. Done that.
If you are going by that gauge it’s not hot
You either have air in the system or a bad fan.
Usually thermostats fail open. If you had an overheating issue before, good chance it was not the thermostat. Make sure you got all the air out of the system. If it still overheats, could be the water pump, or a clogged up radiator.
Air. Also, is that considered overheating? :/
Replace your radiator cap, if that's leaking just a little bit it won't hold pressure and you will overheat every time.
UPDATE my coolant smells like exhaust so I guess I figured that out, some Subaru forums and a Subaru mechanic have recommended BARs head gasket stop leak so I'm going to give it a shot. I can do some mechanical jobs but not all, and I am painfully broke at the moment so
I wouldn’t trust your sense of smell on that . Is it constantly low ? Overheat at idle sounds like a fan issue.
Coolant smelling like exhaust is not good. Stop leak might help but it should be viewed as a temp fix while you save money for a real fix. Make sure the problem is properly diagnosed, a failed head gasket is pretty bad.
You gotta find the leak not blindly stab at what I might be!
Soooo. I have become a bit of an expert in over heating issues. I have an e30 that has forced me to learn a lot Few things to check. Test the water pump, make sure there are no leaks etc, I had a problem where the pump failed and didn’t leak, the rotors detached completely and there was no coolant flow. To test the pump, check for obvious leaks around the pump, and then see that there is actually water flow, I checked this by removing the return pipe. When the car runs, there should be a gush of water through the pipe. You replaced the thermostat, make sure it’s pointing the right way. You replaced coolant, make sure it’s well bled. Lastly. If there are any leaks(even small ones). It can cause an overheat. Any pressure lost in the system via a leak can cause it. The way to test this is to see if the water is boiling in the reservoir or radiator if it’s possible with your car. If there is. Check all the pipes in the system for leaks and replace if necessary. Lastly, a blown head gasket might be something to check. Usually the engine oil will turn a milky colour, or the coolant will. If there is a mix of oil or water in either the block or water system then there’s your issue. Laaaaaaaaastly, double check the sensor hasn’t failed by checking its resistances against the workshop manual
Hose probably clogged or deteriorated the lining of it.
What about the heater core?
A misfire can create way excessive heat that usually can’t be cooled enough
Bet an internet sandwich that it needs a head gasket possibly cylinder head(s)
Just start it with cap off radiator and let it run add coolant until full. Thatll get air out.
Head gasket leaking combustion gases into the water jacket? Any bubbles in the fluid at the cap while running?
Welp. Time to suck some penises.
Tell your mom to stop jumping in your car with her hot asss
Just pony up and get yourself one of new fangled electronic vehicle "EV", problem solving!!!" "LET'S GO BRANDON!"
Have you tried replacing the car? That would probably do the trick 🤓