out of ideas,OVERHEATING ISSUE, goes back down if i floor it

[Six10Styles]

My cars been doing this for a while, and i've recently replaced the therm. temp sensor, radiator, and thermostat. my ej22, only when driving (idles fine all day long) starts to overheat, and wont go back down unless i stop for a few sec. or floor it, and it goes right back down to below half way. this gets scary when in traffic b/c the temp goes all the way up & i have to rev the motor to about 4500-5500rpms to get the temp to go down & get bad looks like im pissed off or sumthin. the waterpump was replaced about 2 yrs ago, and i really hope its not that, shouldnt be since it always cools down after flooring it. Maybe some airpocket in my dash? heard bubbles right after rad replacement, but i bled the system (rad. cap off) & havnt heard it since, but it still overheats. i'm not trying to warp anything, or blow a hg. can someone on here tell what it is,or any other ways to bleed the system?

I also tried flushing the system w/ coolant flush (waste of time & loot) and w/ a hose in the coolant line out of the motor (top hose, light water pressure)(this should flow freely through the coolant intake right? or only when cars running?)

[Sarra]

Did you use a Subaru genuine thermostat, or an aftermarket Napa/Schucks/other garbage tstat?

Any problems with misfires or popping out the exhaust?

I have a few thoughts on this... It could be a junky aftermarket TStat. I've seen those be bad right out of the box. It could also be a clogged radiator. Or, it could be an exhaust valve is wasted (really badly retarded timing could cause this too), and you've got some combustion happening in your exhaust port. This heats up the water jacket in the head, and can overheat the engine.

Test the radiator, just let it warm up, drive it, and feel for hot spots and cold spots on the radiator. Be damn careful of the fans though. You may have to remove them, actually, since the AC condenser blocks you from doing this in the front.

And, it could also be the water pump. :(

The last thing it could be is a bubble in the system. Let it cool off, pop the radiator cap off, start it, and let it idle with the heat on high at max blower speed. Add distilled water or premix coolant until it stops bubbling. Make sure the overflow is above the Minimum line too.

Oh, I suppose it could be a headgasket as well...

[Six10Styles]

aftermarket thermostat, fukin pepboys. I'll pick up another one, the gasket seal was kinda sloppy when i put it in anyway. hopefully that'll work

no misfires/poppingout of exhaust

the radiator is a brand new koyo rad., it better not be clogged but i'll check. timing should be fine, maybe 1 notch off if anything?(i really dont wanna go thru all that again, its cold out)


THANKS,
Hopefully its a fairly easy fix. I'll let u kno

[Sarra]

Ahh, I'd burp the system again, and put in a Subaru genuine thermostat. BURP IT GOOD. Go to Napa or Schucks and get a funnel and adapter to put it right onto your radiator, makes burping a frickin cinch. Rev it a little, squeeze the upper radiator hose, keep the heat on full, even turn the AC on and off a few times. Should get any bubbles out.

Also, if you hear a sound like water cascading around when the car's cold, you got water in the system. Been a nightmare with our Outback, I cannot keep the coolant system burped in that car (I think it had a factory defective headgasket, it weeps anyway).

[greenspeed]

I'd check to see if your system has leaks. The coolant system only works if it's sealed and has the overflow. If you get air weird things can happen.

I want to say water pump, but it is a straight shaft on subies and can't really fail, unless a bearing goes. I'd replace it regardless cause you don't want to take out a belt.

My bet is this is one of those stupid fixes that gets over looked. Ie radiator cap or no coolant in over flow.

[Huffer]

Actually a water pump CAN fail. A friend just had a t-belt done and didn't replace the water pump. 15k later, waterpump seized and it blew all the coolant out, resulting in a tow and a $600 repair bill (all for a $80 part).

[greenspeed]

I ment in the manor like a sheer pin or some way that if it went you may not know. If it seizes it usually jumps timing or takes the belt with it.

Each subaru tends to be different i'vr noticed.

[lozanoa11]

OMG im having the same problem. Its getting worse and worse now. I pegged the coolant temp needle today. When mine is cold coolant is low and when hot it gets way full. I tried a new rad cap no help. The previous owner apparently replaced the t-stat but maybe i should try a suburu one. I just hope its not a head gasket it was replaced 80k ago per the previous owner. Tried block testers but cant get it to fail.

[Sarra]

When the engine is COLD, it should suck coolant in from the overflow bottle; when it's hot, coolant should flow out into the overflow bottle.

Any shop with a 5 gas exhaust analyzer should be able to tell you easily if you have a headgasket problem; If there is any CO in your overflow bottle or in your radiator, your headgaskets are gone.

Either way, when it starts overheating, you need to cool the car off and burp the system, at the very least.

[lozanoa11]

I work at a dealer (non subaru) and we don't have a 5 gas analyzer unfortunately. We do have a block tester that tests for exhaust in the coolant but I cannot get it to fail.

[greenspeed]

I've got it! You're a 2.5L's most likely Hg's. Makes perfect sense. Cold they are fine. Get hot they expand (heads might nto be square) combustion gas gets into the coolant. The gaskets might be seperating causing this too. It's hard to say. pull the heads and see if they are square then try new head gaskets.

Not exhaust? Then it's only filling under the compression stroke.

$5 bucks on that idea. :smt025

[lozanoa11]

I tried that Head gasket seal stuff you put in the coolant just to see but it obviously did not work. Man :smt011 . I just dont have the time to do head gaskets on this. Would basicly have to take time off work and do it at work. How much labor is it usaly?

[greenspeed]

you can spend the 2 hours and pull the engine which is what I suggest then you're looking at another 2 tear down 2 back together with the annoying torquing method and 2 hours back in teh car. 8 hours

[Huffer]

You work at a dealership and you tried a HG sealer additive?!!! That should never be a course of action!

HG replacement is $1000 because you do the timing belt at the same time, or should.

[lozanoa11]

It was kind of a whim. Its worse now over heating in 5 mins of driving. gunna try a t-stat tomorrow maybe i gummed it up.

[greenspeed]

I have a set of hg's I'll sell you for $50's Plus some used timing components that only have 20k miles on them. think of your outback here man

[lozanoa11]

I just hope i did not ruin the block/heads when it overheated. Im contemplating just swapping a used engine in.

[greenspeed]

easy and cheap, just not always curtain what you're getting. Make sure you check the rod bearings. Plus the engines are nitorious for HG failures

[lozanoa11]

Well I just took the t-stat out and it looks fine. poured water in the upper rad hose and it flows threw the engine out the bottom. Pour water in the top of the Rad and it flows out the lower hose. Run the engine and nothing flows out any holes. Does that sound like a bad water pump to you guys?
I would think there should be some water/coolant in the engine that would flow out. Or should the block compleatly empty when the lower rad hose/ t-stat housing is removed?
I can tell the subaru t-stat is much different than the one in it so ill replace any way.

[lozanoa11]

yea t-stat did not help. When you replace the water pump, I know you have to take off the timing chain cover but to do that does the crank pully have to come off?

[Sarra]

Well I just took the t-stat out and it looks fine. poured water in the upper rad hose and it flows threw the engine out the bottom. Pour water in the top of the Rad and it flows out the lower hose. Run the engine and nothing flows out any holes. Does that sound like a bad water pump to you guys?
I would think there should be some water/coolant in the engine that would flow out. Or should the block compleatly empty when the lower rad hose/ t-stat housing is removed?
I can tell the subaru t-stat is much different than the one in it so ill replace any way.

If the lower hose/housing/TStat is off, then there won't be anything left in the block, most likely...

[subaru_crazy]

i had the same exact prob with my ej22 swaped forester. and i flushed the rad put in subaru thermostat all new fluid and now ive havent had a prob with it since.

[greenspeed]

crank pulley comes off to get to the timing covers. you also need to do a timing belt and tension too along with idlers unless you want to end up like me

[lozanoa11]

does the coolant HAVE to flow threw the heater core? Im thinking its possible that is plugged up.

[lord flashheart]

Actually a water pump CAN fail. A friend just had a t-belt done and didn't replace the water pump. 15k later, waterpump seized and it blew all the coolant out, resulting in a tow and a $600 repair bill (all for a $80 part).

i work at a mechanic shop and my boss wont warrenty labor on a timing belt if you dont have the water pump done at the same time.

to me these sound like a water pump or air in the system.
can you get hot air out of the vents?

[lozanoa11]

before i would get heat. Right now i am not getting any heat at all. And it just warms up and keeps getting warm. Like It is not cooling at all. Im gunna try later taking the heater core lines off and looping them to see if its clogged up b/c unfortunately my garden hose is froze for the winter.

[lord flashheart]

before i would get heat. Right now i am not getting any heat at all. And it just warms up and keeps getting warm. Like It is not cooling at all. Im gunna try later taking the heater core lines off and looping them to see if its clogged up b/c unfortunately my garden hose is froze for the winter.

i would bet money you have an air bubble in your system.
thats what makes sense to me..
although you might be right with the cloged heater core.
you never know what that head gasket sealer gunk will do.

[lozanoa11]

Ok so I took the heater core lines off and ran it. Nothing came out and it seems like the upper rad hose is not even filling up so it seems that coolant is not flowing. So I still think its the water pump.

[MDLP412]

any "magic" head gasket sealer usually tells you disconnect the heater core lines so it doesnt clog them up. if you are sure you dont have any combustion gases in the coolant and you believe the head gaskets are still good then just do a water pump, timing belt, and maybe some idler pulleys if they sound coarse when you spin them by hand. make sure the radiator and heater core are not plugged and use that subaru T-stat. If you have a head gasket problem then none of this will help. i suggest you fill the thing up with coolant at an idle with the heater in the high position and very carefully watch the overflow for tiny bubbles every so often, thats how i knew the gaskets were no good in my 2.5. it would be fine for awhile until it got enough pressure in the system and blew all the coolant right out the overflow. i spent 500 bucks in subaru parts and did every seal i came in contact with after i pulled the motor. have the service dept. at subaru e-mail you the service manual pages for the head gaskets, timing belt, and valve train if you do head gaskets, it helped me being a diesel mech. and not knowing much on these motors.

[lozanoa11]

The stuff i used did not tell me that lol. The main reason I think its the water pump is there is no coolant flow.

[Bradleyty89]

If you havent yet, burp it, ive had many radiator problems because of burping

[lord flashheart]

The stuff i used did not tell me that lol. The main reason I think its the water pump is there is no coolant flow.
does it leak or make noise? in my experience the majority of the time it will leak or make a sqealing noise if its a water pump

[Custom Import Heads]

Over heating in 5 minutes of drive time is the HG's. You work for a dealership or just a shop? The tensioner does not have to be replaced unless the oil seal is leaking. If the pump freezes it will wear out the belt. If you would have listened to the advice you asked for initially, you would have been able to remove the engine, repair the problem and reinstalled it about 12 times.

[lord flashheart]

Over heating in 5 minutes of drive time is the HG's. You work for a dealership or just a shop? The tensioner does not have to be replaced unless the oil seal is leaking. If the pump freezes it will wear out the belt. If you would have listened to the advice you asked for initially, you would have been able to remove the engine, repair the problem and reinstalled it about 12 times.
i work at a shop. now im not a master tech or anything, and correct me if im wrong but usually with head gaskets you get considerable condensation from the exhuast and a difficult time starting after the engine has been running. correct?
so if he is getting neither of those things, besides that he mentioned that he did a block test and wasnt getting any exaust fumes in the the coolant. so the likely hood of this being a head gasket is slim at best.

[Custom Import Heads]

The original comments were not directed at you. But, yes, you are correct. However, the HG's haven't been done for over 80K. It is possible that they used an aftermarket waterpump with an alternator style impellar that simply are just poorly designed and do not cool as well as a Peraut(?) brand.

[lord flashheart]

The original comments were not directed at you. But, yes, you are correct. However, the HG's haven't been done for over 80K. It is possible that they used an aftermarket waterpump with an alternator style impellar that simply are just poorly designed and do not cool as well as a Peraut(?) brand.
its possible. but i stick to my diagnostic guns and say, burp the system first cuz that will take just a few minutes and wont cost u, if that doesnt work do the waterpump make sure you get it from the dealer. cuz like "custom import heads" metioned
aftermarket parts from checker o'rielys and autozone suck ass.