audi49

Is the oil cooler on a '88 944 base model just 'air cooled'?
Or is there any water-to-oil heat exchanger involved?

One reason I ask is... is there any coolant leakage possible from the oil cooler?

Thanks.

V2Rocket

water-oil heat exchanger
the only thing keeping oil from water mix is a little green o ring

audi49

Any path of coolant to leak from the oil cooler to the outside?

V2Rocket

im pretty sure the water flows on the outside of the heat exchanger and oil is on the inside.
so if the housing seal is leaking then water gets out.

audi49

I think that is right. Thanks. I did some searching and this link covers it quite well (although still a little confusing). Seems like the conclusion is that the oil cooler will leak only coolant to the outside but could leak oil into the coolant.

https://rennlist.com/forums/924-931-...r-coolant.html

odonnell

Absolutely. The oil is pressurized between 1.5 to 5.5 bar whereas the coolant is generally less than 1 bar. A friend of mine caught his oil cooler seal leakage early on because of a little oil in the coolant.

thomasmryan

True until you shut the car off. Oil pressure zero and the coolant pressure is not.

Pressure testing you cooling system is always wise if you are 'missing some' or the cap doesn't 'pop' when removed after the car has cooled a bit.

Leaks are a perpetual battle and a tester keeps you on the winning side.