unusual head gasket failure, EA82

[MilesFox]

I had a guy bring his loyale to me after he had some steam in the tailpipe. I told him his conditions and he continued to drive the car till it just quit running. This is the car that has the heads installed bacwards(sorry my camera was out of commission and i missed the pic)

 

anyway, i pulled the motor iand removed the heads. The gaskets were all distorted and crushed looking around the bolt holes, and one of the rings was blown out on one side, and on the other head it was distorted near the bolt hole.

 

2 ctlinders had failed on one side and 1 was beginning to fail on the other side.

 

it looks to me that someone either did not do a proper tightening sequence, or went with full torque on one pass in the sequence. It looks like maybe they did the heads in-car and had a hell of a time putting it all back together, used regular rtv on the cam towers, and one of the cam lobes had a huge nick in it whre the chroming was flaking off.

 

The car did not get terribly hot before it let go, and the heads are not warped according to the machine shop. these look like remanufactured heads anyway. Compared to a set of pull off heads from another motor, the pull offs show .005 on a flat edge between the cylinders

 

taking this engine apart, the bolts came out easily, as if the heads had worked loose from a bad install

 

and with the measurements of the machine shop, i am wondering if there is a slight concavity to the surfave of the heads that gets squeezed out wioth the torque sequence.

 

this raises 2 questions for me to ask:

 

1. what possible scenarios could have caused this type of failure

 

2. is there a warpage limit or tolerance that is ok, or should there be a slight concavity between the combustion chambers that is squeezed out when the first 3 bolts are torqued?

Edited January 31, 2010 by MilesFox

[MilesFox]

pictures

[Uncle Ed]

Miles

warpage limit = 0.002 (0.05mm) Thats from both the Chiltons and Haynes manuals. Incorrect torque or torque sequence, failed to clean bolt holes with a tap and/or didn't lube the bolts before installing. I was taught 0.0015 but thats another story.

Ed

[MilesFox]

thanx. That makes me feel better about the heads. The ones from the failed engine checked out as flat, and the other heads were pull-offs from another engine with a bad piston showing the .005, when these head gaskets were not failed.

[nipper]

I never worked on an EA engine, so ill plead ignorance, but could have the heads being on the wrong side of the engine had anything to do with it?

 

I cant tell if it was overtorqued since I wasnt the one to take it apart, but could you tell, or was it a case that since you werent looking for it you didnt notice.

 

 

nipper

[Quidam]

"1. what possible scenarios could have caused this type of failure"

 

Possibly the different thermal expansion rates of the heads and headbolts?

 

I know people who "say" it didn't really get that hot, but they still get home with them:)

 

Doug

[nipper]

"1. what possible scenarios could have caused this type of failure"

 

Possibly the different thermal expansion rates of the heads and headbolts?

 

I know people who "say" it didn't really get that hot, but they still get home with them:)

 

Doug

 

 

"I looked down at the gauge and it was on hot" thats always a good one. What caused them to look at the gauge, usually the answer is "the car was runing funny". Thats like cooking using the smoke alarm and wondering why the steak is tough.

 

nipper

[bheinen74]

my first guess is, they had the left and right heads on the wrong sides of the engine, tightened all up. Then they fixed that mix up, and proceeded to reuse the already squished headgaskets.

That was mistake number 1 and 2, of probably many others.

[nipper]

That was wht came to my mind too. Someone tried to reuse the HGs

 

nipper

[MilesFox]

i was suspecting re-used gaskets. all of the graphite stuck to the heads and deck and not so much left on the gasket, as if some sealant was used.

 

the car was running ad driving with the heads on backward. they brazed a copper tube to run the egr pip eacross the block, and the AC bracket was loose since there was no hole there for it to bolt down to.

 

otherwise i am thiking they doid the work with motor-in-car and just had a hell of a time and slapped it together what they could.

 

lookoing at the gaskets, in person, you can see all the holde are distorted like the gasket was crushed too much.

[MilesFox]

I have this car all back together and running again. I drove it downtown and back with no problem.

 

I discovered that the intake gaskets were some generic gasket material or cardboard with silicone on them. One of the m was squished out between the water passage on one side.

 

The AC bracket was bent from being installed with missing hardware.

 

The pressure check ball on the oil pump was missing, pryed out for who knows what reason, and the oil pump was also missing the inner seal and the bolt on the very left side of it

 

i found the white test plugs plugged in, and the timing was way low.

 

seeing how this thing came apart, i was astonished it ran like this.

 

motor makes some slapping noises mid rpm but that was pre-existing