oil in radiator res

Oil cooler is that cylindrical shaped thingy above you oil filter that it bolts to. Last one I bought for my 6 NZ cost over $800 you will have to flush the crap out of your radiator when your done you will probably still see little floaties of oil after that.

 

A friend of mine is having the same problem. 05 c15, he changed the oil cooler. That didn't fix it.

 

I don't know on a c-15 but the problem doesn't have to be oil.
It could be fuel in the coolant as it looks like oil too.

Oil would come from a cooler as you suggest, or a head gasket, cracked head, bad air compressor etc.
Fuel would come from a cracked injector copper most likely.

Have it checked to confirm oil/fuel, then go from there. Is it pushing coolant out the overflow? That would be compression in the cooling system from a cracked liner, a liner with a pin-hole in it, head gasket, etc. Only a good engine shop is gonna be able to "nail" the problem.

 

Ok,,,if theres pressure in the cooling system pushing coolant out, it's either compression, or air.
This could be as simple as a bad air-compressor! If it's head gasket is leaking, or heads cracked, pressure and some oil would be forced into the cooling system.
Think about it like this...oil psi,,,compression psi, & air psi are all higher than the cooling systems pressure. Anywhere coolant and oil or fuel are seperated by a gasket, oil/fuel gallery are possible causes.

1st ya must find out what it really is. Then the shop can test from there for the cause. It'l save you ALOT of money in the long-run to have someone find out what's really going on. Just guessing gets expensive fast!

Hope this helps.

 

I guess it could be an oil cooler, but really doubt it as it would have to push ALOT of oil in the syetem to create any excess psi. My bet is an air-compressor and that's where I'd look 1st. After that,,,it's a pretty big deal.