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Hi All,

Quick question re Oil pressure of my fellow GTS drivers

Ive had my GTS for about 5 months now and its been a great car (need to change my profile pic from my old cayman to the new one)...

But a a month ago I got an Oil pressure measurement fault warning and PDLS plus headlight warning within a few days of each other. I took that car in and they found a pressure sensor problem re the Oil and a seized stepper motor on the PDLS+. Both we replaced quickly under warranty.

Whilst I waited for a booking slot (about a week) I was told it was fine to continue driving the car, I watched the pressure gauge with interest as it stayed in the red at 5.0 bar at pretty much all revs over 3K and when cold it was at 5.0 bar even at idle. I assumed this was the dodgy sensor. However, I just got the car back with the new sensor and the gauge is reading the same; about 5.0 bar at all revs when cold and 5.0 bar at over 3-4K revs. the gauge part of the measurement seems to start at about 4.7 bar. this doesn't seem right at all to me. but I can't for the life of me remember what the gauge said before these problems came up. could you guys look and see what pressure you're getting?

Anything in the red to me is a warning and shouldn't be there, according to the Porsche techs at the garage, its 'within limits' but I just don.t believe that else the gauge might as well not be there...

Any feedback would be most welcome
 

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The Oil pressure should be 48 psi @ 5000 hot. 20-24 psi hot idle . The old rule of thumb is 10 psi per 1000 rpm. That doesn't seem to apply to new cars. Carl
 

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The Oil pressure should be 48 psi @ 5000 hot. 20-24 psi hot idle . The old rule of thumb is 10 psi per 1000 rpm. That doesn't seem to apply to new cars. Carl
thanks Insider. So 48 psi converts to approx. 3.3 bar. Thats way lower than i'm seeing as 5 bar coverts to about 72psi and i'm seeing that pressure at anything over 4000 RPM...
 

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I see on mine from 1.6 on idle to 2.6 under way. Though I'm in break in period so don't push over 4k.
 

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ok the general rule for the old timers on air cooled motors was.. 1 bar per 1k of revs..and you adjust with the spring valve..near the tranny meats the motor.. you shim it with washers..

Lemon
 

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Yep, 5 bars is 72 psi which is waaaaayyyy too high for idle. Mine is similar to Carl's at about 23psi at idle.


Something is still wrong. Probably an indication/sensor issue because I don't see how the pump is going to produce that high of a pressure at idle.
 
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Thanks all,

I have a call with the service manager this AM to discuss. will report back as soon as I get some info from him
 

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Quick update:

Went back to the Service manager and insisted on the car staying with them until fixed, they agreed and arrange a car via Porsche assist (highly spec'd BMW station wagon; nice car)

they agreed the Oil pressure and temp gauges were wrong and having replaced the sensors already would need to do further analysis. This was last Friday. they called me yesterday to arrange the hand-over and I got it this AM

All seems fine now (they replaced the whole instrument cluster) Oil pressure is now reading 2.2 bar on average driving (was reading 5+) and Oil temp is 91-93 during normal driving (was 103) hopefully all is resolved and I can get back to normal...

Thanks for the input from you guys, it helped when I was shouting at the garage during their 'denial phase'
 

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Just remember that the 981 oil pump is run by an electric motor controlled by a computer and the old adages of pressure vs RPM do not apply. In an attempt to save power and gas, the computer may run your oil pressure much differently than the oid school mechanical engine-driven pumps. I typically see 21psi at idle (1.5 bar) and at most 38psi (2.5 bar). You only need enough pressure to establish an oil film on the bearings. Electric control offers flexibility. With mechanical pumps that were crank or cam driven, it was impossible to avoid increasing the pressure with increasing RPM.

In the original poster's issue. If the reading is bad, I can see the computer doing wacky things. It may just drive the pump at max pressure intentionally, just to protect the engine, or it may be a side-effect of having a bad pressure sensor. High pressure will certainly cause more oil to be flying around, perhaps too much accumulating in the heads.
 
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