Is this a EA82 head gasket issue?

[idosubaru]

I got the car with a blown engine. I replaced the engine. So there could be some residual oil/coolant mixture from the old engine in the lines/radiator. I can't remember if i replaced the radiator or not, i think i did.

 

Intake manifold gasket is new - as of last week. EA82 in a 1987.5 XT manual FT4WD.

 

The car does run and drive, but idles very low - 300-500 rpm and dies often. If I hold the throttle at 2,400 rpm's it stays there just fine. No check engine light. It drives but it's low on power.

 

When I shut it off and walk to the engine compartment the overflow tank is bubbling and quits about 1 minute or so after the engine shuts off. Really no other reason it should be doing that right? This is even right after running for a minute before it gets to operating temperatures.

 

Compression is 150-155 on cylinders 2,3, and 4. i can't test #1 since the spark plug threads are shot!?!?!?!?!! grrrr....

 

Head gasket?

[zukiru]

you can get overflow tank bubbles from a bad cap.. I know I did.

and I have one of those caps with the release valve.. when I open it even a minute after shutting it off I get overflow and bubbles. (what I am saying is it's supposed to do that) I'd try a new cap and possibly thermostat (they go bad from sitting up) and see if it changes. your idle/running issue is likely an unrelated thing. I know you checked for codes and such..

[Frank B]

Or a cracked head, which will provide the same signs of a head gasket failure but with super heated exhaust air bubbles in the coolant. Does the cooling system build up a lot of pressure after just a few minutes of idling? I'm not sure if that's a sure sign of head cracks but one that I had with a cracked head would build crazy pressure, but the Loyale I just bought does this too, and there are no signs of problems otherwise??? The exhaust in the coolant will super heat it so the radiator can't cope with it, so it will overheat fast and often. Does yours run hot?

 

Unless you have all the air out of the coolant system, and the rad filled to the top, you'll get air out of the vent hose. There will or should be some space for expansion. As the coolant comes up to temp, it will push out that air, and some coolant into the overflow tank, as it cools it's supposed to draw it back in. So it may do this every time, all the time.

Does it lose coolant, or have you not driven it much?

Are the plugs wet and stink of coolant?

Does the exhaust smell like coolant? It may since the old engine was blown of course.

[daeron]

sounds alot like a head gasket, but lets look at other possibilities...

 

The bad threads is an obvious problem. Have you considered repairing them to get a decent compression check?

 

I would also recommend a new radiator cap be checked.

 

How are the basics on this engine? ignition hardware, etc.. did all the running gear come from a known running motor? If you aren't sealing a spark plug well in #1 then the idle can't be TOO fantastic.. so there is enough excuse for a poor run condition (due to low cylinder compression) without it necessarily being a blown head gasket.

 

I don't like to point the finger at a head gasket without a compression or leak-down check to confirm. The intake gaskets are as failure-prone as the head gaskets, (at least on the SPFI...?) so there are plenty of places air could be introduced. Checking for steam in a dark area with a laser pointer might help pinpoint any leaks, and any leak could cause air introduction.

 

HTH

[idosubaru]

i'll get on that radiator cap. it looks fine, rubber appears nice and clean.

 

i've never repaired spark plug threads so i'm not sure how to go about that.

 

it does seem to run worse, then when i first cranked it up. now it's worse - probably because the plug won't seat (it stripped removing it for the compression test).

 

don't know about running hot, haven't driven it enough.

 

i think the ignition stuff is good. when i put the motor in 2-3 years ago i think i put new plugs, cap, and rotor in it and they "look" fine now.

 

The intake gaskets are as failure-prone as the head gaskets,

Intake manifold gasket is new - as of last week.

[ellets]

I just finished repairing threads on 2 sparkplugs. Heli-coil from your autoparts store is the way to go.

[idosubaru]

I just finished repairing threads on 2 sparkplugs. Heli-coil from your autoparts store is the way to go.

 

did you have to drill? drill, tap, insert heli-coil and you're done? i've used helicoils before for other things but never done a spark plug. how do you keep the shavings out of the cylinder?

[Gloyale]

did you have to drill? drill, tap, insert heli-coil and you're done? i've used helicoils before for other things but never done a spark plug. how do you keep the shavings out of the cylinder?

 

You can use grease on the tap.

 

But really, the aluminum shavings are going to burn up or be ejected quickly. The steel cylinder liners are way harder than the aluminum. They'll be fine with a tiny bit getting in there. It'll burn right away.

[idosubaru]

You can use grease on the tap.

 

But really, the aluminum shavings are going to burn up or be ejected quickly. The steel cylinder liners are way harder than the aluminum. They'll be fine with a tiny bit getting in there. It'll burn right away.

no kidding, thanks Gloyale!