Was looking at buying a 90 or 91 b2600i. The guy who is selling it said that oil is gettingi nto the water. I know if a head gasket goes, water gets into the oil. I have never heard of oil getting into the water. Is this a head gasket also? The truck was low on water, and the oil was full but I don't know if it has recently been checked. The engine still has compression because it cranks. Just wondering if anybody has heard of this and if a head gasket would fix the problem.

 

is it an automatic ? could be thetrans cooler. if not, it's the head gasket or thecylinder head cracked or the block itself. thats about the only place where oil could get in the water.

 

It is a manual transmission. I was suspecting that, but I wanted some confirmation. Thanks Wrecks

 

I have the same truck, '90 B2600i, 4x4, and when I bought it, I noticed the same thing. There was a thick, black, oily residue in the coolant overflow reservoir. I took it all apart, cleaned the tank, flushed the system, and never found any problems. I haven't had any leaks, and I'm not seeing any oil in the coolant, nor any coolant in the oil. I have some oil residue on the side of the valve cover so I think the valve cover gasket needs to be replaced.