I just got done replacing the oil pressure sensor and associated filter on my 2007 5.3 Suburban. If I start the engine cold oil pressure will hold around 45 for around 10 minutes and very slowly drop to near zero. Then, as the truck warms it drops more rapidly and never makes it to 45 on startup. Below is a link to a video I took of my oil pressure gauge while starting the car warm. Before the sensor replacement it exhibited the same symptoms. Anyone have thoughts or know if the oil pump would be my next stop?


Thanks!

 

Perhaps pump, or something plugging the oil pump. If possible, I'd recommend you put a mechanical gauge to verify the pressure is low.

 

Or something plugging the passage to where the sensor is mounted.

 

I finally was able to test with an analog gauge. I get the same results as the sensor itself. Im unsure why it would be such a slow decline after every startup.

Anyone have guidance?

Thanks!

 

as the oil warms the viscosity lowers so the oil pressure will also drop.

does the oil pressure rise when the engine is revved up?
any engine knocking or lifter ticking?

if yes for both...I would try a new oil pump. a cheap fix attempt would be a heavier weight oil.

if that doesn't fix it...the oil clearances may be excessive...high mileage motor?

 

I suffered from this issue. My fix was a high volume high pressure oil pump. I see 45 psi regardless of oil temps.

 

Been having similar issues with my '11 tahoe. Except it holds lower oil pressure. Like 25 PSI on the highway. 170K on the clock and fresh oil change from the dealer. It doesn't seem like it should be that low, but I hope it came with some warranty from the dealership, otherwise I'm either looking at a cheap fix, or a few grand. I don't have a lift to get under it to take the oil pan off and check if it's the O-ring on the pickup tube, but my luck, that'd be the problem.

 

Do you mean the little screen under the oil pressure sender, or the oil filter itself? I think I'd just use slightly thicker-weight oil and not worry too much about the gauge readings.

By the way, if you meant the little screen under the oil pressure sender, how did you remove that ???

 

Yes the screen under the sensor I also replaced. Next I will be replacing the oil pump. Anyone have a write up they know of for replacement?

To remove that screen, i took the new screen to a hardware store and found a bolt that fit perfectly snug, then "threaded" it into the old screen and pulled it out, worked perfectly.

 

Thanks for the informationServerGuy, that was a great idea. I'm saving that in my file. It sure seems like that whole area is pretty touch to access. Do you have any photos you could post, or even a part number for that little screen???

So far we've done nothing on ours; the oil pressure gauge is still showing fine, the message hardly ever shows, and obviously our oil pressure is not in the dangerous area, or the engine would've self-destructed.