Geo55

So I did an oil change when I replaced the oil pan gasket on my 87 928 s4 and now I see that the oil pressure gauge is reading 5. Could I have done something when I removed the pan? I know that the rubber boot on the oil level supply switch cracked. Will have to search for an adequate replacement. the oil I put in Mobile 1 w15-50. Should I worry about the oil pressure?

R.Pires

Reversed wires on the oil pressure sender switch??

linderpat

yes, sounds like a simple oil sender issue. Check the wiring underneath at the sender. something may have come off (different sizes so not easy to put them on the wrong stud). The sender itself can go bad. Quick and dirty and cheap fix. That's probably all it is.

Geo55

Thanks guys, I will check to see if I pulled the wire off or something. I know that it worked before I put in the motor mounts, pan gasket and rebuilt the steering rack, pulled alternator and replaced crush washers on the steering pump. I must have done something. If the wires/plug were off would it read 5?

Wisconsin Joe

Well, what does it read with the key on, but the engine off?

What does it read at idle when hot?

It will run 5 bar all the time (pegged high) when cold, and when much above idle (above 2000 RPM?) when hot.

Geo55

Hey Joe, with the key on it reads "0". When I start it "5". to be honest, I've never really gotten it up to temperature because I just recently purchased it and trailered it home. Been up on stands since then. Will have to check it out. Although, when I purchased it the oil gauge was registering around "3" when at an idle.

Wisconsin Joe

Well, it sounds like it's behaving normally as far as I can tell.

Ducman82

Sounds normal to me for a cold engine

Geo55

Thanks guys, Maybe a little over paranoid. New owner just don't want to screw it up.

Bertrand Daoust

Sounds normal to me too.

Mine:
- At start up, cold engine, idle: 5
- Warm engine, idle: 2-2.5
- 2000 RPM and over, cold or warm: 5

20-50 Royal Purple.

oldfrat

Geo, welcome. I had the same concern as I drove my 928 home from the auction. But no worries. You might be able to get the number down, though, if you park it near the front door of the Rongovian Embassy for a few hours. :0 (Dryden boy here.)

Brad

Geo55

I will do that! Anything to get that number down.

Ducman82

wait what? I'm guessing some kind of locals joke? only way to get that number down is to use oil that will murder your engine.

mark kibort

mobil 1 should drop the oil pressure substantially.

OTR18WHEELER

^ agree, ... Also, synthetics leak out.
I run 20 50 dino, oil pressure retains 5bar during extended driving in ++90 degree ambient temps, after a few hundred miles it sometimes drops to 3bar when at idle.
If I may add, I believe 5bar may help against TBF.
viscosity is the cushion, that prevents the crank pushin'.
Otis out!