Oil Pressure Guage


Full Member
while driving, oil pressure gauge drops to 0 - then occasionally pegs out at 80, then drops back to 0. Checked the dipstick, says its full. Not throwing any codes - assume a bad sending unit...?


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Full Member
The random pegging at 80 makes me think the problem lies with the oil pressure sensor.

I have had to change mine out in my 2004 a time or two.

It would not be unreasonable to assume the one in your 2004 might be due, as well.

It is always a possibility that the stepper motor in your cluster may be going bad, but I would lean more toward the oil pressure sensor.

With the proper sensor socket, a swivel and a couple of extensions, the sensor can be changed out in less than an hour with a couple of soft drink breaks along the way.

I would advise only purchasing an ACDelco OE (not the lower quality ACDelco Professional version) oil pressure sensor as opposed to a cheaper aftermarket unit.

I have had better luck with the ACDelco OE parts for this repair.

Your 2004 engine will NOT have the plastic filter screen that you will see some people advise you to also replace, so don't bother looking for or purchasing a replacement part for that.

Best of luck with your repair.



New Member
I recently purchased a 2006 Avalanche and the oil pressure gauge just tops at 80 when the engine is started.  I anticipate that it is the sending unit.  Does the 2006 5.3L have the plastic screen filter mentioned?


Full Member
rbrt43, no you shouldn't have the filter/screen. DOD/AFM/4-cylinder mode started in 2007 on the Avalanche.


SM 2006
SM 2005
Full Member
My 2013 threw a code and the oil pressure gauge went to zero yesterday.  I immediately stopped and check the oil.  It was fine.  Had the code read and cleared this morning.  Then the  pressure gauge pinned hard right.  Then back to zero.  Then it coded again.  Seems obvious it is a bad sending unit.  Not going to bang myself up trying to change it as DIY, particularly because I do not have the suggested, necessary tools.  If I did, I might make an afternoon of it as a test of my patience.

Bunch o' threads here about how to do it should you want to take a stab at it.