Normal Oil Pressure

[wilson234]

Just curious on my 1983 911SC, what's my oil pressure gauge suppose to read at high rpm.

Mine seems to max at 3 out of 5 bars and doesn't get any higher all the way to redline. Is this normal? I know modern 911, anything over a few thousand RPM the needle is at 5 bars indicated full pressure.

Curious if this is indicative of an issue or is this normal?

Thanks!

[JJ 911SC]

Mine (3.2) was like that until I put the update oil restrictor update, but did not really worry about it.

It might be your senders or gauge.

You can easily check you gauge by unplugging the wire on the senders and ground it; when ground it it will read 0 and when left "in the air" (open circuit) it should read 5.

Most non-fail safe Porsche ever design

[Reiver]

Not normal. I've an '83 SC and when cold see 5-4.5 bars until warmed. At 3k rpm I show 3.5 bar using BP 10w-40 today.
What oil weight and filter are you using?

[wilson234]

I use Mahle filter from our host and 10w-40 oil.

Where exactly to I pull these sender wires to test the gauge is working correctly?

Whats the updated oil restrictor you refer to?

So are you telling me when the car is at high rpm I should be at full 5 bar pressure?

[JJ 911SC]

Answer interlace below.

Originally Posted by wilson234

I use Mahle filter from our host and 10w-40 oil.

Where exactly to I pull these sender wires to test the gauge is working correctly?

The wire that connect on top of your senders;





Whats the updated oil restrictor you refer to?

Half way down the page, titled "Updated Camshaft Oil Line Restrictor Kit": Porsche 911 & Carrera Cam Towers & Timing Chains - Page 1

So are you telling me when the car is at high rpm I should be at full 5 bar pressure?

Rule of thumb, 1 bar per 1000 rpm

[mclmk8d]

I have a 1972 T with 1977 2.7l engine (Webers) and it reads 135-140 on throttle (my gauge is not in bars) and then goes down to 120. That seems very high to me...opinions, please

[Joe Bob]

VDO was the lowest bidder. Trust but verify.

[James Brown]

worry about the pressure at idle, the rest takes care of itself, high miler engine, anything over .5 bar is good (idle). Oil system is a strong point, not many problems.

[bpu699]

911 oil pressures are wacky... my 911s and 930 both do the same thing.

Oil pressure at idle is 3 bar. Stays there for as long as you let it idle. After it warms up, settles to 2.5 at idle.

Oil pressure peaks at 4 bar at 3000 rpm and stays there through 6000 rpm. Changed the oil pressure valve/springs, put in oil restrictors, yada, yada. Checked the oil pressure sender, etc.

I can't understand what would cause this, but it seems similar to what you are having. I have seen others on here post similar issues. You would think that if the tolerances were loose, the first thing to go is the idle pressure. But the idle pressure in both cars is great. If it were a rubber seal off the oil pump, then the idle pressure whould be low too... The shops in both cases said not to worry about it...

I don't think I have seen an explanation on this site of how oil pressure can plateau, and then not go up? Seems like that would be a oil pressure relief issue somewhere...

Good luck!

[Roger 911]

Originally Posted by mclmk8d

I have a 1972 T with 1977 2.7l engine (Webers) and it reads 135-140 on throttle (my gauge is not in bars) and then goes down to 120. That seems very high to me...opinions, please

Did you replace the sender with a '72 sender? If not, I think your guage might be reading double. I have a 3.2 in my '72 and I see about 25 psi at idle, and 60 under part throttle. It goes up over 120 at redline, using a '72 style sender.

Roger

[mclmk8d]

Originally Posted by Roger 911

Did you replace the sender with a '72 sender? If not, I think your guage might be reading double. I have a 3.2 in my '72 and I see about 25 psi at idle, and 60 under part throttle. It goes up over 120 at redline, using a '72 style sender.

Roger

Roger,
If the engine is a 1977 but the gauge is 1972, should the sender be for a 1977 engine or fro a 1972 car with the oil pressure gauge that goes up to 140?

Sender for 1977
PN 91160611102

Sender for 1972
PN 901-741-551-02-M100
A photo of my gauge (engine off)

[Joe Bob]

You match the gauge and sender...whatever you have. Typically you change the sender to match the gauge.....but not mandatory.

Most like the gauges in the dash to match.

[Roger 911]

Gauge = Sender

I have a '72 gauge in my dash and a '72 style sender on the motor. I'm not sure about the '77, but my '84 3.2 required a little bit of adaptation to fit the sender on the motor (different sized fittings). But again, that may not be an issue with a '77 motor.

Roger