Oil Pressure

Joined
Dec 16, 2020
Messages
45
HI

I have an 07 gmc sierra 1500 with a 6.0 and Idle oil pressure drops to about 15 when in its gear at hot idle and about about 20-22 psi when just in park hot idle, some days the hot idle in gear is 20-25 sometimes lower, I had the oil pan dropped a couple months back for an oil pan gasket and cooler lines and they check O ring and they siad it was in good condition and changed oil recently too, the cold start pressure is about 50 and when driving around 2,000 rpm 35 psi hot driving and when at 3,000 it’s almost 40 at hot driving what can I do to improve hot idle oil pressure was thinking about changing oil pressure sensor since it seems to be different pressure at different times at idle which doesn’t make sense at same hot idle, would using a range tune and delete afm help the idle hot oil pressure when it’s in gear because as soon an it goes into park oil pressure goes right up to 20-25 psi so doesn’t make sense

thanks in advanced
Jacob
 
Are you saying they removed and inspected the o-ring on the oil pickup, but didn’t replace it? I don’t know why they wouldn’t just replace it as long as they had it out.

There have been a couple threads about low oil pressure on these engines due to a plugged filter, but sounds like yours has been recently changed.

Oil pressure is higher in park vs gear because the idle speed is slightly higher (no load in park).

How many miles on the engine?
 
Are you saying they removed and inspected the o-ring on the oil pickup, but didn’t replace it? I don’t know why they wouldn’t just replace it as long as they had it out.
I can't imagine anyone doing all the work to get to that o-ring, even on a 2wd, and saying "o its fine" without popping on a new one.
 
when driving around 2,000 rpm 35 psi hot driving and when at 3,000 it’s almost 40 at hot driving what can I do to improve hot idle oil pressure
About the same here. Switched to 5W50 and got a few PSI improvement.

IMG_6007.JPG


IMG_6004.JPG
 
i know there was a change in filter recomendation , i have seen some posts on this , if you do a search im sure you will find something , guys were reporting after they changed to the different filter it took care of the issue
 
No iron 6.0L had AFM, But all Gen IV blocks are machined for AFM.....To my point....The O-rings that seal the AFM lifter bore holes can leak & cause low hot idle oil pressure.

This could very well be worn Cam Bearings & it's VERY difficult to diagnose this 'til all the other possibilities are exhausted....Like the Oil Pump itself.

The Oil Pressure sensors are usually pretty accurate....The failure mode is Leakage & it internally shorting to the 5vdc Reference. Of course, No screen was used on non-AFM engines. If in doubt.....Install a mechanical pressure gauge for testing.

While that IS low for a LSx engine, As long as you're not experiencing any lifter noise......You're likely okay, Maybe run a 15w40 or a 5w40.

I've never had a pan off a LSx engine & NOT change the pick-up tube O-ring.....That's kinda bizarre!!
 
 
... as soon an it goes into park oil pressure goes right up to 20-25 psi so doesn’t make sense.
What does the factory service manual say the oil pressure range should be with hot oil, (using the specified viscosity) and at idle (xyx RPM)? If the shop looked at it knowing your concerns about oil pressure, did they verify the idle pressure was within the manual specs?

If the oil pressure is inconsistent at idle, putting in a new oil pressure sensor can't hurt to try. Your oil pressure above idle sounds pretty normal.
 
Back
Top