1994 Audi Cabriolet 12v 2.8L oil cooler? [Archive] - Audi Forums

: 1994 Audi Cabriolet 12v 2.8L oil cooler?


copycon
04-12-2011, 12:33 PM
I'm curious to know if a bad oil cooler can possibly cause intermittent overheating in a Audi 12v 2.8L?

I've been searching everywhere to try to find any information at all to possibly diagnose the overheating issue and I haven't had much luck. I've replaced the thermostat, radiator, water pump, coolant, upper radiator hose and timing belt. I've also taken the car to 2 different shops which have both failed to properly diagnose the issue. I also bought the Bentley manual, but that hasn't been much help towards diagnosing the issue unfortunately.

The engine has overheated in the past on hot days and when stressed (hill climbing, high RPM, stop and go etc). The symptom appears after the vehicle is being driven for an extended period and both fans run constantly after about 10-15 minutes until the vehicle is turned off. It doesn't seem to occur if the vehicle is left idling though. I am just hopeful that there is no long term damage to the internals.

I'm afraid that it could be the head gasket causing the problem, but I thought I'd try the oil cooler first because it made sense and it is the *last* possible component that I can imagine would impact the cooling of the engine. There is no coolant in the oil or oil in the coolant as far as I can tell, but the coolant does seem to evaporate (or leak from the reservoir?) and I can see that there are "bubbles" coming through to the reservoir when the car has been shut off.

The car has been sitting through the winter and I'm planning to replace the oil cooler, flush the cooling system and do an oil change with 0-40w as a last stand before I throw in the towel on this one.

Any advice would be appreciated...

Thanks!

copycon
04-12-2011, 12:38 PM
Also, I've had the engine compression and leak tested and everything has come back OK. So, I'm at a loss on this one. :(