DSMblue

The oil pressure gauge in my 968 seems a bit off. It generally reads 4 bar at cold start, then 3 bar when running warm, and shows 1 bar at idle. Anyone have experience like this? Thinking that maybe I should just replace the sender. No leaks or other issues with oil system.

SeaCay

Miles, oil weight and temperature?

thomasmryan

I would temporarily install a mechanical gauge and check the hot idle pressure. I would want to see 2.5-3 bar.

AkechiMotors

Per Clark's:

"The 944's oil pressure should run 4-5 bar at idle when the engine is cold. It will gradually decrease to 2-3 bar at idle as the engine oil warms to normal operating temperature. Once the oil is at normal operating temperature, the oil pressure should indicate around 4 bar at 5,000 rpm. It takes the oil longer to reach its normal operating temperature than the coolant. Therefore, don't be surprised if oil pressure continues to decline after the coolant temperature has stabilized at its normal operating temperature. Occasionally, you may see your oil pressure drop to less than 2 bar. This may happen on very hot days when the car has been driven particularly hard. You should be extremely concerned if the oil pressure dropped to less than 1 bar. This is indicative of an problem with the oil pressure indication or the oiling system itself. Under these circumstances, the car should not be driven until the cause of the low oil pressure indication is determined and corrected."

I'm not sure it applies to the 968, but it seems to describe what you're experiencing. FWIW, this is typical for my S2, and I believe the 968 engine is a further development of the 16v NA (could be wrong - I'm not familiar with it).

DSMblue

Update on this: Was able to use variable resistor to verify functionality of dash gauge per Clark's Garage process to test. Since that passed, I intend to get a new sender and see how it reads. Will update again once it is installed.

Jfrahm

I had (acceptable but) low oil pressure at 160K miles. During service I found the rod bearings to be at their wear limit. Replaced and all is well. It needed an oil pan gasket and engine mounts also.

ElRicardo

Hey DSM- both my cars fall to 2-3 at idle and spike to 4-5 when revving. 1 seems a bit low, though. +1 to the previous poster- when I run 10-30 oil the gauge is way more active than when I run 20-50.

H.F.B.

I had something similar some years ago, it was a bad oil filter. I changed the engine oil and oil filter and it was cured.
Now 1.5 bar at hot idle and 4 bar at 5000 rpm, which is what the Owner's Manual states.

Apart from that: Oil pressure is a measurement of resistance to flow. Oil pressure serves to supply oil in between the parts. It does not keep the parts sperated. It's the oil film strength, which does this. The fact is, oil, as a liquid can't be compressed. So as long as you have enough oil pressure at idle and above according the owner manual, there is enough oil supply for the moving parts in the engine.

Porsche 968 Owner's Manual, Page 48, WKD 968 021 93, 5/92

DSMblue

Thanks for that update! I was just going off of my previous experience with my 944 (still have) and Clark's Garage information. I think I still might replace the sender just for peace of mind when I do my oil change. Other than some extra money, it really can't hurt anything. And if the new sender provides same output signal, at least I have a spare sender!