HorstP

Folks,

Need some advice. Just recently oil temperature has started showing a little higher than all the time before. Engine is a 87 930/20 with 100k miles. Did always, no matter how I drive, be width of a needle below the 8'o clock mark. Now it is always on or above the mark. So nothing dramatic but noticeable enough to make me think and also a little worry. Today was a 68° day, so not hot and it did the same again. Any thoughts?

Steve Weiner-Rennsport Systems

Horst,

Several things can elevate engine running temperatures and IMHO, the place to start is by accurately measuring outside air temps against observed oil temps. This is really the only scientific method toward gathering useful information to diagnose a potential problem or not.

Several things can contribute to higher oil temps that include:

1. Oil viscosity and brand changes
2. Partially obstructed oil coolers; engine & front cooler
3. Slipping fan belt
4. Vacuum leaks in the intake system
5. Remote thermostat not opening all the way (the one in the RR fender well)
6. Failed O2 sensor
7. Old plug wires, cap & rotor causing misfires (oftentimes you cannot hear nor feel it)
8. Partially obstructed cat
9. Ring sealing issues

There are a few more, but these are the things to start with.

Hope this helps a little,

HorstP

Thanks Steve, that helps.
Eliminated 1 and 3. Don't think 8 as it still has same power as before. Will need to smog soon, that should test 6. Leaves enough to check.

Reiver

Horst, why not get a temp overlay for your gauge so you know exactly where you are? Makes life easier.
I've an '83 930-10 Euro and today, 104 degree ambient temp, was running 195 to 200 degrees oil temp. Same set up as you with a Carrera oil cooler that I added.
Trying to guess the temp is a pain in the ***.

HorstP

I found out in the meantime that the gauge has indeed temperature values, they are to the very far on the left, very small and normally not visible. The 8 o'clock marking is actually 90°C (194°F) on the lower end of the white bar. So my engine was running always slight lower than that and now it is running slightly higher than that. How much is a little guess as it is within 10 degrees or so. But as posted before, repeatable and consistent.

JABSEA

I usually add this to temperature discussions:

HorstP

Your picture shows the position and size of the numbers I was talking about. Does unfortunately not help on my problem. Something starts to go south...

Reiver

You're still not running hot by any means.
How about an inspection behind the fan for any debris and a good cleaning of that area and the primary oil cooler.