tracke30m3

Im seeing higher than normal oil temps, my temp was normaly below the 9
o'clock postion but now its going past that and would even get close to 10 o'clock.

Found out that the oil cooler fan is not coming on even when engine temp is already nearing the 10'clock mark. Did the relay testing thing and fan works in both high and low speed so obviously the fan itself is OK and I guess I can assume the resistor is too. Swapped the oil cooler fan relay with the one from the A/C fan, oil cooler fan still not working, I guess that rules out the relay since the A/C fan works fine.

What could be wrong? The CCU? Thermostat? Forgot to check if the right fender gets hot when engine is at operating temperature.

Will be doing the manual fan override switch, but I would still like to have the oil cooler fan functioning automatically.

GabiOsz

It could be the temp sensor in the oil pipe.

tracke30m3

Why didnt I think of that? I guess the fan isnt getting the signal that the oil is already hot? Where is this temp sensor located?

Thanks.

chris walrod

There is a oil temp sensor located on top of the oil cooler. Just remove the RH headlight assy., and you'll see it there.

When this sensor fails, and is -open circuit-, the fan will run on -high- speed as a default. Doesnt seem like this sensor fails very often..

I am not certain exactly what sensor triggers fan operation. Anyone know?

JasonAndreas

I think the climate control unit in the dashboard will only activate the blower first stage if the oil temperature is at 110C/230F and for some reason I thought there was something related to actual vehicle speed but I can't find the source for that (is that what you mean by "which sensor"?) I can't find anything documenting the oil temperature required for the blower second stage.

DarrylH

Well, check that first. If the thermostat's not opening, the oil temp sensor never gets hot and the fan never switches on, no matter the indicated temp on the gauge, because the gauge measures temps at the engine. IF the thermostat's opening, then it sounds as if your temp sensor at the oil cooler is dead. It still could be the CCU, but that's much less likely.

DarrylH

I don't think there's any speed-dependent input to the CCU for the oil cooler operation (although it's a good idea...) My understanding is that the CCU turns on low speed at 230F (212 on 964) and high speed at some unknown but (obviously) higher temp (239 on 964) based on the input from the oil cooler temp sensor.

Tom W

Have you looked at the "troubleshooting" DIY on p-car.com? It goes through all the steps to determine what's wrong.

JasonAndreas

The CCU does get a speed input from the ABS controller but your right I can't find where I thought I had read (I'm not old..) that the oil cooler operation was effected by speed, just the fresh air servo is speed dependent and the temperature servo's are set to full cold when you are in reverse so you don't suck exhaust into the cabin.