Started the truck up today to drive home from work and I noticed the oil pressure was pegged. This morning pressure was normal. I switched my scangauge to watch it digitally and at idle pressure was ~100psi when I got on the road it was around 116-118 psi cruising. I just parked it when I got home and didn't drain the oil because I had a busy afternoon. I'll pull the plug and see what kinda of material I see in the oil and on the magnet this weekend

Would the pressure sender lose calibration like that, or do I have a more serious problem? Pulling the plug will tell me more but I just wanted to prob people for other possibilities in the meantime.

 

Probably sending unit I replaced mine cause reading low put new in and reads high like urs so it can happen

 

Re-check with a manual gauge if possible, but yea dig sending unit. I doubt the stock pump will generate that much pressure with a stuck relief valve...

 

Where would I tap off of with a manual gauge? Also where is the stock pressure sensor located so I can replace it?

 

Stock sending unit is behind the intake. I've never replaced one with the engine in the truck but I would say it would be hard to do without pulling the intake off. You could test pressure there as well, or the oil cooler block on the side of the engine, but that will require drilling and taping.

 

Don't bother testing anything - it's the sender. We've replaced dozens of them here at my shop. EXACT same symptoms.

B!tch to get to, but it can be done.

 

Part number for oil pressure sender? Doing a cam swap soon and might as well replace it.

 

NM, think I found it: GM 12562267, ACD D1818A

Rock Auto showed a different part for regular cabs though for my '01 5.3L: GM 89057526, ACD D8037

Anyone know the difference between the two? The second one didn't have any hits on here or LS1tech.

 

there is a tall and a short. Probably gonna need some sort of super deep socket too...
a real SUMBIT to do in the truck!

 

you can get the oil sending unit socket at oriellys for 10 bucks its worth the money if you not pulling intake, I did mine with intake on just took off intake cover