New Head Gasket but still got water in oil
 

I just replaced the Head Gasket on my 1987 M102 engine. Unfortunately it didn't fix the problem of coolant getting into the oil.
After 5 minute of very rough running I removed the rocker cover and the rockers are again covered in creamy slime.

When the Head was off I checked it visually for cracks and couldn't see anything.

Could the Head be badly warped ? I checked it with a straight edge when it was off and it seemed fairly true.

What should I do now ? Compression is perfect across all cylinders.

Would a leak down test isolate the problem ?


Also, the car will not idle and only runs at about 2500 rpm and above if you continually pump the accelerator.


Doug McCutchan

There arent to many options here. I think you have no choice but to pull the head again. I would bet that the problem is in the head somewhere or the gasket. Obviously there is a common passage somewhere to the oil, water and combustion chamber. I realize that I am not telling you something that you dont already know. Wich I could be more help.

Your high idle condition is agrevating the situation. If you could fix that first, it might allow you to find the leak more easily. Sounds like a fuel delivery problem. Im not familar with the M102 engine so I have no specific suggestions.

Keep us informed on what you find. I wish you luck.

The right thing to do here is pull out all of the plugs and pressure check the cooling system. Then see if coolant pours from one of the holes, if not, you may have a plug blown out or a crack in the block or in the intake.

Good luck

Thanks for the tips.

I pressure tested the cooling system to 20 psi . It gradually leaked down to 10 psi over 15 minutes. Unfortunately I can't see where the coolant has gone.
The pistons are clear of cololant.

There definitely is a major coolant leak somewhere as the camshaft and rockers are covered in a brown/yellow creamy substance (however the oil on the dipstick looks o.k.). Even when I clean this off , it comes back with 2 minute of running.

I assume this indicates a problem with the head as no coolant has gotten into the sump yet.

I take it I need to remove the Head again and get it crack tested ?


Doug McCutchan

p.s. the car is backfiring and won't idle - I assume this must be related to the coolant problem ?

What did the plugs look like? did any one of them look different from the others?

John,

All of the plugs look perfect.

Doug