Oil in the expansion tank! Help

[gainsboz]

My 1996 4.0 Explorer as oil in the expansion tank. I have removed the heads. Looking at the block i cannot find any cracks on the surface and the bores seem fine. I also cannot see any cracking on the surface of the heads, but i have not checked behind the valves. There is traces of oil in the radiator. The engine as been LPG converted. Can anybody advise me of my next move.

Thanks
Gainsboz.

 

[budwich]

check your transmission oil..... looking for milky color there as it is possible (from experience...:-( ) that your transmission oil has found it way to your rad (thru the cooler) and visa vera.