2005 Yukon 5.3 oil pressure issues. Please read, I need your help

[cuttingedge]

Hi. About 3 weeks ago I drove my Yukon to the Vets office. When I started it up, it read zero oil pressure. Stabbed the throttle and pressure went to normal. Thought the oil sending unit might be faulty and replaced with ACDelco part. Same issue occurred. After some research, I added 2 quarts of oil and jacked up the rear and instantly had oil pressure. So, it's the pickup tube o-ring right? Took it to the shop with a Felpro pan gasket and the o-ring part number my VIN said I needed. Told the shop there are different types of o-rings, and that they would have to verify at disassembly. Got the call it was finished today. Had to pick it up after hours due to needing a ride, and upon start up zero oil pressure and warning light/bell. Stabbed the throttle once and pressure went up to nearly 50psi. Drove it home no issues. Kill the engine, wait 10 seconds, start the truck zero oil pressure. Stab the throttle once normal pressure. Let the truck reach full warm up temp and oil pressure at idle is 30 to 35 psi, which is better than before the o-ring was replaced.

Any insight on this would be very helpful. I'm out over $750 and it's not fixed.

 

[Fless]

Could be a cluster gauge issue (stepper motor). Is the engine noisy when the gauge reads zero? You may need to verify with an actual gauge in place of the sender.

 

[cuttingedge]

Could be a cluster gauge issue (stepper motor). Is the engine noisy when the gauge reads zero? You may need to verify with an actual gauge in place of the sender.

Thanks for the reply! The engine is not noisy. To be fair, I haven't let it idle very long reading zero when hitting gas gives it pressure. Should I let it idle unless/until I hear some clatter? I can buy a pressure tester. I honestly thought about using a manual gage (assuming the pressure is ok) and moving the pressure sensor to near the pump or oil filter.

 

[Fless]

There's been a little chat recently of adding a 't' to where the oil pressure sender goes, to enable a manual measurement at the same time. If I can find the link I'll post it in this thread.

 

[Fless]

Take a look through the thread below; I'm not sure if the mounting threads on the oil pressure sender are the same for these earlier engines, but someone here may know.

Low(ish) Oil Pressure issues.

Hey everyone I have oil pressure concerns. My issues don't immediately reflect other issues I've found so that's why I'm creating a new thread. So here it goes. I've owned this '07 Denali (6.2L Non DOD) since ~140k and the symptoms have always been the same. With that said, at 150k I did...

www.tahoeyukonforum.com

 

[cuttingedge]

Take a look through the thread below; I'm not sure if the mounting threads on the oil pressure sender are the same for these earlier engines, but someone here may know.

Low(ish) Oil Pressure issues.

Hey everyone I have oil pressure concerns. My issues don't immediately reflect other issues I've found so that's why I'm creating a new thread. So here it goes. I've owned this '07 Denali (6.2L Non DOD) since ~140k and the symptoms have always been the same. With that said, at 150k I did...

www.tahoeyukonforum.com

What really gripes me is the shop said it was ready, knowing I had to pick it up after hours. There is absolutely no way they didn't know it wasn't fixed, and didn't say a word when I paid the bill. I am more than certain it will be a fight to get them to do anything about it.

I'm going to do a manual pressure check. If it doesn't have pressure, I'm thinking I'm not going to put anymore money into it. I bought it for $5500 from the original owner and they told me it had run only full synthetic from the first oil change. It was beautiful. It got hail damage in late 2023 my insurance company paid me $5600 and I could keep it, but the value lowered to $2100. I've changed the fuel pump, replaced the rear axle bearings and seals, rear brakes, and had to have the front differential rebuilt. I've only had the damn thing 2 years. I just don't have the money to keep repairing it, and the insurance is over $200 per month. Plus, being so cold here in CO I can't do the work myself in the driveway until spring.

I got 366k miles out of my 2000 Z71 until it crapped out. Bought it with 200k miles. Through the course of owning it I had to replace the water pump, knock sensors, the alternator, 1 lower control arm, and the fuel pump. It was a better rig than this 05.