garyreed Report post Posted October 22, 2018 I assume they are only pressurizing the coolant. A leak might show op better if it was hot but some may also only show when cold. If the cooling system and the crankcase were not cleaned properly there could be some residue left. Can you tell how much is getting in? Generally a lot of oil in the radiator will push it out the overflow. It does not say in your first post if the oil was changed at the time of the cooler. Gary Share this post Link to post Share on other sites
rayin Report post Posted October 29, 2018 Coolant system is under ~17psi when hot, oil system is under ~35psi when hot at idle, near 60psi when at 1,800 RPM. It there are cavitation holes in cylinder liners it allows coolant into oil pan- there is no or very little crankcase pressure to resist the coolant pressure.(doubtful if coolant system has been properly maintained) Were this my MH, I would also request the shop perform a compression test on the engine in search of a blown/leaking head gasket. Share this post Link to post Share on other sites
manholt Report post Posted October 29, 2018 At the beginning of this thread, Rich mentioned head gasket or a cracked head. Share this post Link to post Share on other sites
rayin Report post Posted October 29, 2018 Thanks Carl; by the time I read through to the end I had forgotten the 2 reply had already covered that; getting old is inconvenient. I sure hope the problem is corrected by now. Share this post Link to post Share on other sites
manholt Report post Posted October 29, 2018 I know all about brain gas! LOL Share this post Link to post Share on other sites
