proper 930 oil pressure?

[Yargk]

My oil pressure (druck press) shoots up to around 3.8 bar by 3000 rpm, but then won't go higher than 3.8 bar, even by 5000 rpm.

Should I be worried?

[Richard930]

IIRC, pretty sure the manual says 4 bar at 4,000 rpm (I'd check but it's away in the car for the winter) and the rule of thumb is 1 bar per thousand rpm, though some cars do drop under 1 bar at warm / hot idle. So based on this you may have cause for some concern and want to do some investigation.

[Miguel Antonett]

1bar x 1000rpms.

[voitureltd]

Originally Posted by Yargk

My oil pressure (druck press) shoots up to around 3.8 bar by 3000 rpm, but then won't go higher than 3.8 bar, even by 5000 rpm.

Should I be worried?

As I recall in a stock oil system there is a oil pressure relief valve that will keep the oil pressure from going past 4 bar. It sounds like yours is working close to right. might just be a inaccurate gauge or sending unit. When cold does it hit the 3.8 bar sooner than when hot?

[JFairman]

You can remove the oil pressure relief valve spring (it's the vertical one) and put a 10mm wrench size nut under it to shim it up and increase it's preload a little. That will raise oil pressure about 5-8psi depending on how good the oil pump is and crank and rod bearing clearances.

That may not be a good idea if everything is up to spec and in good shape in a 911 motor but if oil pressure is a little low because the spring is worn and lost some preload it helps.
I did that to every older 4 and 6 cylinder single cam BMW motor with the magnesium casting rotor type oil pump I built or modified and it worked great.