Milky Film in Coolant?

[Mopar Man1]

This truck(91. 5 D350),guy was going to paint it,started taking the interior and some exterior pieces off and then quit. It developed a leak when another guy was looking at it. The gasket behind the oil filter bracket must of gave way and it was squirting oil out. Soon going to start working on the truck,it's got little less than 100k on the clock and everything is in pretty good shape. Coolant was low and I flipped the radiator cap over and noticed a very light brown film on the cap,it feels slick(like oil :{ ) Do not see any other leaks or fluids anywhere other than a little more of this film down in the radiator(looked with a flashlight) The oil looks fine,no discoloring in it. Could this mean blowed head gasket? Shouldn't hurt the motor to put the new oil filter bracket gasket on it,let it run a minute to make sure everything is cool will it? Thought afterwards of changing all fluids and flushing the radiator out. Think I should do this and hope the film doesn't come back or would it be a waste of anti-freeze and oil to change fluids. Just got my curiosty up,Thanks

 

[bgilbert]

The oil you're seeing in on the cap could be from a radiator stop leak application. Changing all fluids and flushing the radiator and system sounds like a good idea. I don't think it would be a waste of fluids. I would get an oil sample analysis done, ~$20. Theres Blackstone Labs, not sure what the website is though. They'll send you a free sample kit. The oil cooler could be bad and allowing oil to enter the coolant. Maybe someone can tell you how to test it/inspect it while you're changing that 'oil filter bracket gasket'- I'm guessing the oil cooler is what you're referring to.

 

[Mopar Man1]

Thanks Gilbert I Googled it and I'll throw the link at the bottom for the free kit if anybody else is looking. Would you just have to seal it all up and mail it back to BlackStone Lab to be tested?



If you say it's the oil cooler than I guess It bolts to the block,the oil filter screws onto it and the oil line for the turbo runs to it also I believe. The top back corner of the bracket is squirting oil but its squirting between the block and the bracket so we just bought the gasket for it. I've had a few CTD's but never got my hands dirty on them much but will defineately on this one

 

[Paychk]

I agree with Bill the gasket/leak is for the filter/oil cooler mount. The oil system has more pressure than the radiator so oil ends up injected into the cooling system. Remove & replace the gasket should remedy the situation. Pressure check the oil cooler with 70 PSI air, you should hear it leak, on safe side submerge in water & look for bubbles.



Good luck!

 

[PToombs]

There are 2 gaskets on the cooler. One seals block to cooler,the other seals cooler to cover. It's a pain to check the cooler. Try a small plastic or rubber cap and hold it with a c-clamp to one hole,and a rubber tip blow gun on the other,under water is best. Good luck!