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Subaru still burning coolant after head gaskets


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I have a 1993 Subaru Loyale with an EA82 engine. I picked it up with what was supposed to be a blown head gasket. I pulled the engine, tore it down, and inspected everything. The cylinders had no cracks, and the heads looked good other than the typical cracks between the valves, and those were minimal. I reassembled the engine and ran it for a bit to clear all the coolant from the exhaust, and took it out for a test drive. It did fine, but it felt like it was still burning just a small amount of coolant (slight stumble), and on the way back it dumped smoke for about 15 seconds before it quit. I got back and the coolant level had dropped in the radiator. I pulled the plugs and 3 had clean tips (burning coolant), so I pressurized all the cylinders and none of them bled off back into the cooling system. The only thing I could think of was that coolant was coming into the intake from somewhere, so I now have a new intake to eliminate a cracked one, along with new intake gaskets and throttle body o-ring again. All the surfaces are perfect, so if this doesn't fix it, where else should I look?

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a stumble would not suggest to me any coolant or headgsakets issues - you sound confident though but could it be leaking somewhere externally?

 

were you able to run or test the motor at all before working on it?

do you know the symptoms before you started working on it?

 

what headgaskets did you use and did you retorque them? anything other than Fel-Pro's require a retorque procedure, did you do that?

 

so you replaced the intake manifold gaskets (the ones with coolant passages going through them)? the aftermarket ones are school girl panti-wetters and prone to leak....but other issues do seem more likely since you were already trying to fix a coolant issue. :confused:

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The stumble was it is burning coolant in the combustion chamber, which means coolant is getting inside somehow. I test drove the car before I bought it, it was really burning coolant bad, and when I drove it home, I twisted the radiator cap off halfway to keep it from pressurizing and leaking coolant inside the combustion chamber. That tells me the headgasket is bad or a cylinder or head is cracked.

 

I used all Fel-Pro gaskets, torqued everything to spec, cleaned and oiled the bolts, etc.

 

The intake gaskets are Fel-Pro as well and definately not "cheap" gaskets. This time around I'm using another intake, new gaskets again, and putting a thin layer of high temp rtv on both sides to eliminate any leaks.

 

I've also reinspected the intake runners on the head and found no apparent cracks either. If this thing still leaks after this new intake, I'm out of ideas.

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Well, I got it all put back together and took it out for a test drive, it cleaned out after a few miles and wasn't putting out any smoke, and the stumble went away. I'll take it out for another test drive tomorrow morning and hopefully the problem will be fixed. If not, I don't know what's wrong with this thing.

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The intake gaskets are Fel-Pro as well and definately not "cheap" gaskets.
if you replace them again, use Subaru gaskets, you'll notice a difference as soon as they're in your hand by look and construction, they are much more robust. this is fairly common recommendation here for folks that have done what you're doing dozens of times. it's not like they always leak, i've used fel-pro's before too, so i don't think that's your current issue.....

 

how long have you driven it after the headgasket job?

 

EA82's typically take awhile to run normal - they can run *terrible* after you first put them back together from a large job. just takes a bit for everything to seat, get all the coolant/water out of the exhaust, and hydraulic valve lash adjusters to fully pump up. i've seen some that i thought were definitely done wrong at first, coughing, sputtering, clamoring....but after 10 or 20 miles of driving they smoothed right out. that's fairly common on these motors.

Edited by grossgary
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I've got probably 20 miles or so on it since it's been done. I test drove it again this morning and it's still burning coolant. It seems to be getting to at least 3 cylinders.

 

So far its had new headgaskets, checked the heads over for cracks (didn't see any, other than typical between valves), checked cylinders for cracks, redid intake gaskets, tried another intake, new throttle body o-ring, pressure tested the cylinders to make sure it didn't bubble back into the radiator, and it still starts burning coolant right when I start it up.

 

WTF car! :mad:

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I've got probably 20 miles or so on it since it's been done. I test drove it again this morning and it's still burning coolant. It seems to be getting to at least 3 cylinders.

 

So far its had new headgaskets, checked the heads over for cracks (didn't see any, other than typical between valves), checked cylinders for cracks, redid intake gaskets, tried another intake, new throttle body o-ring, pressure tested the cylinders to make sure it didn't bubble back into the radiator, and it still starts burning coolant right when I start it up.

 

WTF car! :mad:

 

First I will say that I comment with the hope that someone more knowledgeable can confirm or deny the following, but I think there is at least the possibility of a freeze plug being dislodged. Since you're in Alaska that makes some sense. I believe they are located in the head under the valve cover gaskets, but someone that works on EA82s will have to confirm that. It allows coolant into the crankcase which doesn't sound exactly like what you have going on, but it seems possible that it could also get into the cylinders, and like I said, hopefully someone can chime in on that.

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One other thing I've noticed is that when I'm test driving it, it'll burn coolant until it empties the resevior and about 4-5" down in the radiator, then it'll stop burning it. I won't see any more smoke until I try to top it off again.

 

I'm also confidant it's not leaking at the intake gaskets, since when I removed the first set I put on there they sealed very well and didn't have signs of leakage on them. I also flat sanded the intake and head to make sure the surfaces were perfect.

 

The freeze plugs are fine, it's not leaking coolant on the ground or into the oil, it's just burning it.

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weird.

 

coolant can enter the combustion chamber, which you seem to be confident is what's happening, via intake manifold gaskets and headgaskets.

 

if it was the cylinder wall/sleeve that seems very unlikely and for it to happen to 3 cylinders seems almost impossible.

 

mis-diagnosed so far, engine was beat to snot previously, or the headgaskets aren't holding?

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I checked the cylinder walls over real well when I had the engine out the first time. The motor only has 177k and it was owned by an older guy all it's life who maintained it very well, but bought a new car and didn't want to spend the money on repairing this one.

 

The headgaskets are holding because I can pressurize every cylinder and none will bleed off into the radiator. Its definitely burning coolant since it's cleaning the plugs and smoking out the tailpipe.

 

I just can't think of what else it might be.

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Would it be possible to block off the coolant line from the throttle body to the heater core line, and seal off the holes on the mating surface of the intake to stop coolant from flowing under the throttle body? This is the only place I can think of where coolant could enter both sides of the engine on multiple cylinders. It's also the highest point on the motor, so that once the coolant level drops a bit, coolant wouldn't flow through the throttle body and it wouldn't burn coolant until I refilled it and brought the coolant level back up. Possibility?

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Did you happen to check the heads for warpage using a .002" feeler gauge and a straight edge?

 

Thats my $0.02

 

No, I forgot since I was in a bit of a rush initially to get it out of the garage before I left town that weekend. But like I said, I pressure tested the cylinders and it wasn't leaking back into the radiator.

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how did you pressure test?

 

could it only be leaking under load or heat?

 

EJ25's are notorious for passing all classical headgasket failure tests when they first start to leak. they'll pass compression, leak down and even exhaust contaminant tests sometimes. not unheard of to have a mechanic stuck on one of those motors when they first start failing. granted, not an EJ25.......

 

well i'm on vacay in a few hours so i guess i won't be able to follow along, hope i come back to a good ending.

Edited by grossgary
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I pulled the spark plugs, made an adapter with a pressure gauge inline, and held the engine with the cam at 12:00 (valves closed). Pulled the radiator cap, and at 100 psi, none of the cylinders bled off into the radiator.

 

It doesn't seem to matter if it's under load or heat, as I can go out in the morning and start it up and it'll start smoking/burning coolant almost instantly.

 

I'm considering pulling the plugs and pressurizing the radiator, and seeing if I can fill one of the cylinders with coolant that way, or if I can find the leak somewhere else.

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I pulled the spark plugs, made an adapter with a pressure gauge inline, and held the engine with the cam at 12:00 (valves closed). Pulled the radiator cap, and at 100 psi, none of the cylinders bled off into the radiator.

 

It doesn't seem to matter if it's under load or heat, as I can go out in the morning and start it up and it'll start smoking/burning coolant almost instantly.

 

I'm considering pulling the plugs and pressurizing the radiator, and seeing if I can fill one of the cylinders with coolant that way, or if I can find the leak somewhere else.

I knew I had a leak in one of my other cars and even useing 100psi into the cyl. did not show anything..tried again with 125psi and then slowly and every once in a while a bubble would come out the rad.. ended up haveing a crack under the valves...
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Well, I'm completely at a loss now. I pressure tested the radiator and found a few very small leaks (mostly just the coolant line into the throttle body-replaced the crappy stock clamps), but I can't hear or see any leaks into any of the cylinders. The radiator is holding fine at 18psi as well. I thought I heard a small leak in cyl #2 last night, I stuck a tube down in and got a very small bead of coolant, but I can't get it to do it again today. I've tried rotating the engine while the radiator is under pressure in case there might be a crack in the cylinder or under a valve, but nothing. I might try pressurizing the cylinders again at 125psi, but if it smokes right after it starts up, I would think the leak would be a bit more obvious?

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Well, I'm completely at a loss now. I pressure tested the radiator and found a few very small leaks (mostly just the coolant line into the throttle body-replaced the crappy stock clamps), but I can't hear or see any leaks into any of the cylinders. The radiator is holding fine at 18psi as well. I thought I heard a small leak in cyl #2 last night, I stuck a tube down in and got a very small bead of coolant, but I can't get it to do it again today. I've tried rotating the engine while the radiator is under pressure in case there might be a crack in the cylinder or under a valve, but nothing. I might try pressurizing the cylinders again at 125psi, but if it smokes right after it starts up, I would think the leak would be a bit more obvious?
.. I drove up to Alaska and back with my '86 having a cracked head, not so serious since it leaked into the exhaust pipe...it leaked every so often..when the weather was cool or cold it leaked and once the weather was warm, it never leaked... you could try leaving the coolant pressure tester on over night with plugs out of the car or even a full day, pumping it up every so often..put some kleenex over the spark plug holes and turn the motor ..it would then shoot coolant unto the kleenex... it may be that this motor has had several HG jobs and the surface has become wavy from scubbing the decking clean..not really discerable with a straight edge and .002 feeler ...
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Suba_GL_87: I used the gasket in the second picture (the Fel Pro in the package). They were the same pattern as the gaskets I took off, which appeared to be OEM.

 

Petersubaru: I left the pressure tester on all day at 18 psi with the spark plugs removed, never dropped a bit. I put a new radiator cap on since the spring was feeling weak, so I will see if that makes a difference at all. I'm actually sitting in the car posting this right now with the engine running, and it's not smoking yet (knock on wood). I guess I'll have to see if the coolant level drops again.

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Suba_GL_87: I used the gasket in the second picture (the Fel Pro in the package). They were the same pattern as the gaskets I took off, which appeared to be OEM.

 

Petersubaru: I left the pressure tester on all day at 18 psi with the spark plugs removed, never dropped a bit. I put a new radiator cap on since the spring was feeling weak, so I will see if that makes a difference at all. I'm actually sitting in the car posting this right now with the engine running, and it's not smoking yet (knock on wood). I guess I'll have to see if the coolant level drops again.

 

maybe need check/replace manifold intake gasket....

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maybe need check/replace manifold intake gasket....

 

Already checked and replaced both the intake gaskets and the intake manifold itself.

 

Well, I put it back together and test drove it around for the rest of the day. It seems to be holding coolant now, and it's only smoked twice for just a little bit at a time. It's also only sucked in about an inch on the reservior, instead of sucking it dry and about 6" down in the radiator like it had been doing. Maybe I just need to drive it and let everything 'wear in'?? :confused: The hell if I know, I've had some tough problems to chase down before, but this car just makes my head hurt.

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Hey,

 

Something to consider. The intake is subject to what, 21" vaccum? I suspect it's been the head/intake interface all along. The new thermostat was a good move. Old, intsalled dry gaskets just simply leak at some point. Coolant then corrodes the bolts and creates a possible leak into the intake.

 

I've taken to coating the gaskets with No.2 Permatex. It stays soft and seals. Light coat is all that's needed.

 

Good amount of torque on those 80mm and 55mm bolts helps too. Long and twisty so lube the threads and under the heads of the bolts well.

 

hth

 

Doug

Edited by Quidam
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Well, I came out again this morning after the drive last night, and the reservior is dry and the coolant level is about 6" down in the radiator again...

 

How many psi can I safely pressurize the radiator to, without having to worry about ruining a gasket or the radiator?

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