991.2 GT3 High Oil Pressure
11-17-2018, 03:00 AM
#31
Rennlist Member
Even GM has different blank configurations for their center console buttons at the bottom of the dash depending on which options you have so it doesn’t show whether you are missing options on their 2014-2018 trucks or not. It’s a nice touch.
11-17-2018, 11:19 AM
#32
Drifting
Exactly, and they have 10 button blanks in the center console instead of spending $10 per car to mold a plastic piece which has the right number of button holes for the number of buttons each six figure 911 has.
Even GM has different blank configurations for their center console buttons at the bottom of the dash depending on which options you have so it doesn’t show whether you are missing options on their 2014-2018 trucks or not. It’s a nice touch.
12-29-2018, 07:21 PM
#33
Appreciate so much the Rennlist community for sharing information. This thread is spot on for this issue that came up for me this morning. Breaking in my 2018 991.2 GT3 (~270 miles, all at/below 5000 RPM, so far) and noticed the oil pressure bar up near the redline at 67-71 PSI, idles ~35-40. Responses above helped bring my blood pressure back to the middle of the gauge.
01-18-2019, 06:27 PM
#34
Intermediate
Thanks Reenlist!
I just change my oil on my .2 GT3 at 830 miles and noticed the oil pressure was near the red with 65 PSI at 5000 RPM.I got worried but this thread put me at ease....Thank You!....Quick note when that oil comes out of the side it really pours so of be ready. I had to do a bit of clean up. ( at 900 miles i'm going to 9000 been a long wait :-)))
I just change my oil on my .2 GT3 at 830 miles and noticed the oil pressure was near the red with 65 PSI at 5000 RPM.I got worried but this thread put me at ease....Thank You!....Quick note when that oil comes out of the side it really pours so of be ready. I had to do a bit of clean up. ( at 900 miles i'm going to 9000 been a long wait :-)))
08-02-2019, 08:31 AM
#36
This is why I like this place.
Last night while I was mulling about putting on break-in miles I noticed the oil pressure gauge, which is normally kinda hidden behind the steering wheel, was reading 4.5 out of a maximum of 5. That seemed high. Not because I know anything at all about how many BAR is appropriate for oil pressures, but simply because the gauge only goes to 5 and in most cases "normal" isn't near the maximum reading for a gauge. I reconfigured the MFD to show it and got a bit of a surprise as I saw it climb up to 72 psi up around 5k rpm or so, which was pretty much pegged to the right of the graph at the red dot.
So I guess it's normal. It's definitely disconcerting.
Last night while I was mulling about putting on break-in miles I noticed the oil pressure gauge, which is normally kinda hidden behind the steering wheel, was reading 4.5 out of a maximum of 5. That seemed high. Not because I know anything at all about how many BAR is appropriate for oil pressures, but simply because the gauge only goes to 5 and in most cases "normal" isn't near the maximum reading for a gauge. I reconfigured the MFD to show it and got a bit of a surprise as I saw it climb up to 72 psi up around 5k rpm or so, which was pretty much pegged to the right of the graph at the red dot.
So I guess it's normal. It's definitely disconcerting.
The following users liked this post:
Mike Murphy (08-05-2019)
08-02-2019, 10:56 AM
#38
08-02-2019, 12:46 PM
#39
08-02-2019, 01:18 PM
#40
Addict
Rennlist Member
Rennlist Member
I don’t think oil level and pressure are dependent (unless it’s empty). As long as the gauge is not over 5 Bar (75psi), there’s no problem.
08-02-2019, 02:08 PM
#41
Full dislosure: This might be something I imagined completely out of the blue.
08-02-2019, 02:25 PM
#42
Addict
Rennlist Member
Rennlist Member
Over-filling with oil is bad, but I don't think high oil pressure is the risk. I think it could cause the intake to ingest oil with the air it needs.
08-03-2019, 12:50 AM
#44
Addict
Rennlist Member
Rennlist Member
However, I believe the GT3 oil pump is totally mechanical (saves a failure point by going without the electronic one and the GT3 uses a very high quality mechanical pump) and runs at a speed proportional to the revs of the engine (think it's geared to the crankshaft). The reason you note different pressures on the gauge at idle when initially starting and thereafter is due to 2 things:
1. The engine has a higher idle speed when cold.
2. When the oil is cold, it is thicker and produces more pressure with the same amount of pumping (pressure goes down at same revs as the oil warms).
The pressure rises with the revs of the car to a degree and then I think there is a pressure relief valve that prevents pressures greater than around 4.5 to 5 Bar (bit less than 75 psi)
08-04-2019, 11:54 PM
#45
Race Car
No, I think you are falsely concluding that the pump is fully variable with the fact that the oil pressure is not always the same. I believe all of the Carrera, Cayman, and Boxster motors have electric oil pumps that are run at different speeds by the ECU, according to the demands of the engine.
However, I believe the GT3 oil pump is totally mechanical (saves a failure point by going without the electronic one and the GT3 uses a very high quality mechanical pump) and runs at a speed proportional to the revs of the engine (think it's geared to the crankshaft). The reason you note different pressures on the gauge at idle when initially starting and thereafter is due to 2 things:
1. The engine has a higher idle speed when cold.
2. When the oil is cold, it is thicker and produces more pressure with the same amount of pumping (pressure goes down at same revs as the oil warms).
The pressure rises with the revs of the car to a degree and then I think there is a pressure relief valve that prevents pressures greater than around 4.5 to 5 Bar (bit less than 75 psi)
However, I believe the GT3 oil pump is totally mechanical (saves a failure point by going without the electronic one and the GT3 uses a very high quality mechanical pump) and runs at a speed proportional to the revs of the engine (think it's geared to the crankshaft). The reason you note different pressures on the gauge at idle when initially starting and thereafter is due to 2 things:
1. The engine has a higher idle speed when cold.
2. When the oil is cold, it is thicker and produces more pressure with the same amount of pumping (pressure goes down at same revs as the oil warms).
The pressure rises with the revs of the car to a degree and then I think there is a pressure relief valve that prevents pressures greater than around 4.5 to 5 Bar (bit less than 75 psi)
Yeah the idle speed when cold is around 1000 rpm, 750 or so when warm. But to me that's not enough for a 4.5 bar level vs. 2.0 bar when warmed up. Seems like big delta with just oil viscosity change.
GT3 standard spec is a fully variable hydraulic oil pump with 7 suction stages. This is a different oil pump than other, non-GT models...No other Porsche I've had (997, 3 other 991s, PTT) has oil pressures this high, and they didn't behave this way at idle...pressures run higher at idle even after warm-up. 991.2 TT ran about 1.5 bar at idle...GT3 is about 2.0 bar. My GTS was similar to 991.2 TT.
At speed on highway when car is warmed up, it's running ~ 62 psi or so...much much higher than what I recall in other models.
992 C2S lists the oil pump as 'on demand, controlled oil pump' - which I think is similar to other non-GT models.
