Hopefully a common issue with an easy fix. Once my 944 is fully warmed up, at idle the oil pressure light flickers. The pressure falls just a hair under 2 bar.

Thoughts or ideas?

Sending unit or motor rebuild (Please no!)

Maybe main/rod bearings?

120000 miles on it . . .

 

What is the pressure at 3000 rpm? Is it closer to 4 or 5 bar?
What oil are you running 10-30?

If you are running 10w30 and the pressure is above 4 at 3K rpm, I'd change to a thicker oil. I use 20w50, but then the summer heat is above 95F.

If you are using a fairly heavy oil 10w40 or 20w50 and the 3K rpm pressure is under 4 bar, I'd start looking toward the internals (crank bearings).

 

from the owners manual:

"An occasional brief flickering of the oil pressure warning light at idle speed and normal engine temperature is no cause for concern if the light goes out upon acceleration."

and 'a hair under 2 bar' doesn't sound too bad

 

Has this car been sitting for an extended period of time? When I bought my 83 with 88K miles in 1994, it did this a few times and had me worried. The PO had practically let it sit without giving it any real use for 2 years. I read the section Tom cited from the owners manual and stopped worrying.

The light has never flickered again and the car now has 205K. No engine work other than belts and cam cover gasket. I do change oil and filter religiously every 3K.

 

On my 1986 944, I noticed some days the oil pressure guage goes nuts and jumps from 2-5 up and down until I drive, which it stays at 4 or 4.5. Other days it flickers around the 2 area. Could my issue be the same as my83944?

 

Try cleaning the connection to the sender unit on the motor. My daily driver was doing that the other day and I sprayed some braker cleaner (which works as a heavy duty elect. cleaner) on the sender and the wire connector, which seems to have fixed it. Sometimes a bad/cruddy enough connection can make your sender give a false signal.

 

Thanks guys.
I will clean the sending unit. At 3K, the engine is a hair over 4 bar. In fact, anywhere over idel it is there when the car is hot. Gets near 5 when the car is cold though.
I run Castrol 20/50 - Only oil I have ever used in it. Oil and filter changes every 3000 miles, if it needs it or not -
Thanks again, I feel al ot better about it.

 

The only time I'd worry is if the running (over 3000 rmp) pressure drops below 4bar.

Sorry I didn't even think about cleaning the contacts on the sending unit.DUH!