1994 straight 6, i have white foam under my oil cap. moisture right? a friend told me it was the head gasket or a cracked block, please tell me it aint so, she sat all winter because of a power steering problem, fixed that then flushed the radiator, checked my oil then saw the whitness under cap. has been running like poo, changing oil and checking for fouled plugs next week, if i see the foam under oil cap again, what next?

 

Was the oil pretty? If the oil was clean and not milky, then, it's probably just condensation.

 

my truck sits alot.........so the top of the oil cap is milky some times.......like chester said as long as the oil itself is clean you got nothing to worry about

 

prolly condensation. sitting and short trips does not get the engine hot enough to evaporate it. this is a very very common problem in winter and happens to all engines. a good long drive with the engine at operating temp will remove the moisture.

 

Exactly. If you have any doubts, pay attention when you change your oil next week. Oil is lighter than water, so if there is any water in the oil, it will sink to the bottom, and will be the first thing to come out the drain hole in the oilpan.

 

Older straight sixers are notorious for this. It could be just the condensation, however if it is running like "poo", it could be a head gasket or cracked head/block. Most likely head gasket. You can also check for oil in the coolant, however it all depends on where the crack is letting water into the oil or oil into the coolant. Also, do a compression check on each cylinder as well to make sure they are up to par.

 

make sure your PCV system is working. it helps remove the excess moisture from the crankcase. the colder it gets the more moisture collects in the crankcase.

 

I'm with the rest of the gang. If you're not losing any coolant, don't worry about it.

-Joe

 

If your not loosing coolant and your oil isn't all milky than it's probably just condensation. My 99 runs great and I have found milky oil on my oil fill cap caused from condensation. Your truck is probably just running bad because it's been sitting all winter.

 

Actually just because your oil looks fine, it doesnt mean its just condensation. My head gasket blew between the pistons and my oil looked find but I also has that milky substance on my cap. Unless the gasket blows to where it affects the water/oil together, then your oil will not be affected.I did a compression check and sure enough, I blew a head gasket. If the truck is running like "poo" after a tune up, then I'd be willing to be that it is a blown head gasket.

 

He flushed the radiator and checked the oil according to the first post. I think it's safe to assume that there were no significant problems to speak of prior to that. I think that's the assumption we all addressed.

Again, if you're not losing any coolant, (which could be a source for the moisture in the event of a head/gasket issue) I wouldn't be worried.