AC 6-cylinder engine; oil in coolant

[groeser]

Hi,
   I have a problem with an AC engine, which I had overhauled a couple of years ago, using a new replacement block. I have constanly oil entering into the coolant and get a smeary sludge in the radiator neck.
   However, I have absolutely no coolant in the oil; thus it is absolutely a one-way-leak; only oil into the coolant.
   I have changed the headgasket and sleeved the oil passage in the head already, but the problem did not go away.
   BTW, I had given the liners 0.010" protrusion, which shouldn't have "lifted off the head" to an extent that the oil passage is no longer sealed by the headgasket.
   ...does anybody have an idea?
   Gerhard Roeser

[Robin A Woolmer]

Gerhard
   Have you had the head crack tested? the water system is at atmospheric pressure whereas the crankcase will have some pressure (but not much)so it might be possible for oil to pass into the water but it would need to be above the water line to be only one way!

[administrator]

I had the same symptoms last year, and pressure testing the head showed some old and previously repaired cracks had opened up.  The engine will be reassembled in the next couple of months and hopefully the problem will be cured.