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Re: Oil in Coolant

Robert Patrick wrote:

>I have noticed some puddles of oil floating on top of the coolant in my
>expansion tank on my '84 5000 S. I know this is REALLY BAD, but I am 
>wondering just how the oil could get into the coolant. My first thought
>is head gasket, but if that is the case then I should see coolant in the
>oil, (which I don't), coolant or oil in the exhaust (ditto) or coolant or
>oil spewing forth from between the head and cylinder (ditto again).
> ...


One thing that comes to mind - does the car have an engine oil cooler?
Many cars have the engine oil routed to the radiator to cool down the
oil. If the coils inside the radiator are leaking, then you can have the
situation you're describing. The oil is generally at a higher pressure than
the cooling system, so the leak will be oil -> coolant rather than the
other way around. This explains why you don't see coolant in the oil.
Now I don't know if an '84 5000 has an engine oil cooler; for that matter
I don't know if my Audi ('87 5000 TQ) has an oil cooler. Check for two metal
tubes going from around the oil filter area to the radiator - or check the
Bentley manual, if you have one.

The solution may be to replace the radiator. Much cheaper and simpler than
the cylinder head gasket job that you are dreading.