Oil Pressure Strangeness

NYSpeed Automotive
1

2009 g8 gt with 91000 miles
So this past spring I had a check oil/P0521 code. I swapped the sensor, still got the code, just more intermittently. Then I swapped the filter and oil and voila, no more issues.

Fast forward to now. When I returned from vacation last monday and started the car I got the code, It went away with pushing the motor off of the 650rpm idle. I shut it off and logged the startup and this time it started out at 15psi and slowly climbed as it warmed up. Once it was warm it would stay at about 35 psi at idle and climb to 50 when revved.

Any ideas?
My thoughts are either sticking bypass valve or faulty pickup tube o-ring…

2

The pickup tube oring doesn’t go bad and get better though its low oil psi all the time.

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Hook a manual gauge up and verify?

Did you do a DoD delete?

3

I need to verify still with a manual gauge. Yea did the DOD delete when I installed the supercharger and ls9 cam.

4

Did you forget the rubber seals on the valley cover?

5

Nope, they are there, keep in mind the issue started before the super install…

6

Pickup could be full of junk, has anything in the engine ever been apart? Like oil pan or valve covers etc? I’ve seen guys plug up pickups with the overuse of rtv on gasket surfaces…

7

I guess Ill find out this weekend. I bought a new pickup oil o-ring and plan on pulling the pan, changing the oil o-ring and plugging the pressure relief valve.

8

I’ve have this happen on can am atvs when the oil pump pick up screen Gets shit on it. Interested to see what it is.

9

that would be about the only reason oil pressure goes up when the oil thins out that I would think of.

10

Yea I’m thinking this or that the pump is pulling air through the oring when its cold because of how much more viscous it is.

11

Did you delete the DOD pressure relief valve that is on the oil filter area of the pan? I had one fail on a customers G8. Killed the motor quick in the upper RPM.

12

I’m going to when i pull the pan. I build great pressure all the way to 6500 rpm redline, The only time I have an issue is when the motor is under 35° and under 700RPM.

13

Finally pulled the pan…was the oring. First time I replaced it I started up with 0 oil pressure…3 hours of pulling the pan for a second time and now it sits at 70psi cold 50 hot. Got rid of the AFM pressure relief valve while I was in there too.

14

Nice. I’ll have to try to remember that one.

15

I have two extra o rings incase anyone is pulling theirs apart…

16

I’m only at 38k. I better not have to for a while. I’m still looking into a quick tune. This transmission is horribly sluggish.