I've got an 01 Yukon w/the 5.3, and today the wife got a "Check Oil Pressure" light and the needle was at zero. I checked the oil level, which was low but readable, and added some to make sure it was within limits.

I re-started it, and no pressure.

Are oil pump failures common in the 5.3? If so, are they easy to fix?

Oil is Pennzoil Platinum, 5w30, and ironically I was going to change it today since it's due.

Before I go get an oil pump, any suggestions on where to start? Most likely I will tow it later today to get it to a shop.

Slow down here oil pumps just don't fail. If there is no lifter noise and the oil is full I would suspect the oil press. sending unit. Get it to a shop and have them put a mechanical gage on it and check the actual pressure readings first.

I figured they weren't a common part to just "fail," like the fuel pumps in earlier models.

I didn't want to run it long, but I did start it to check if the oil pressure was reading or not. The problem is, I've had some lifter noise on startup over the last few weeks and it didn't really sound very different to me. I'm not sure it's my choice in oil, but I never had this problem previously with Mobil 1. Of course, it could be a part failing as well instead of the change in oil.

Off to the shop it goes...

I have a 2001 Yukon Denali with the 6.0L and the same thing happened to me. I lost oil pressure and I have what sounds like a lifter noise from the driver side of the motor. I've had it to two different shops and both said I need a new motor. Let me know what your shop says about yours. Thanks.

The shop says they hooked up a tester and told me there is no oil pressure. The manager told me his "engine guy" says that this happens a lot with the 5.3 engine.

That right there is a big flag, and I think they just want to soak me for $4400 for a long block because I have never heard that before. According to them, if there's no oil pressure, then there's something internal, and there's always going to be damage from that sort of thing. He also said it's not worth replacing the oil pump due to the damage.

I'm going to have it towed to a coworker's house so we can work on it tonight.

I just read this on another forum:

well i got my truck back yesterday. first off they did not void my warranty. the service manager explained to me that a few weeks ago someone had brought in a truck like mine and the air box was full of mud and water so he figured i had been doing the same thing. appology accepted. now on to the good part. they ended up replacing the oil pump and the oil pressure relief valve which might be located in the oil pump i guess. the mechanic working on my truck said that he had seen 3 other 5.3 liter engines do the same thing in the last 4 years. the relief valve woud get stuck wide open which woud cause the motor to lose all oil pressure. i assumed that when this happened the whole motor got replaced but he said no. he said that they are a tough motor and the other 3 motors ran fine after replacing just that defective part and that my motor appeared to have no damage done to the valve train ect ect. so i ask the manager about extending my warranty and he says no, the lifters and the bearings were all checked and appeared to be fine. well i guess i will just have to keep an eye on the oil pressure ( so far it is normally between 40 to 50 psi). my warranty runs out in march, i just hope if the motor decides to die that it does it before then.

OK, so how do I replace the oil pump and the oil pressure relief valve?

Hey guys,

Any idea how to replace that valve?

Thanks.

This YouTube video shows someone porting a 5.3 Oil Pump and when they reassemble it, you can see where the relief spring is. http://www.youtube.com/watch?v=lMqBV7cNQL8

A bad seal where the pick up tube meets the oil pump can also cause low oil pressure. http://www.pistonslap.com/tsb/020601038.htm

//2000CAYukon

This YouTube video shows someone porting a 5.3 Oil Pump and when they reassemble it, you can see where the relief spring is. http://www.youtube.com/watch?v=lMqBV7cNQL8

A bad seal where the pick up tube meets the oil pump can also cause low oil pressure. http://www.pistonslap.com/tsb/020601038.htm

//2000CAYukon


Thanks, man. I can't see the links at work since we've got a webfilter but I'll check when I'm home.

My buddy who's got a shop confirmed there's no oil pressure. When he spun off the old filter it had the old oil in it plus some of the new oil I'd poured in to top off the oil level when I thought the low oil pressure might be due to low oil quantity.

I'll be ordering an oil pump, o-ring (thanks for that link!), timingh chain cover gasket & seal, and new water pump gaskets for this job.

Tentatively, this is fixed. The oil pump appeared fine but we replaced it and oil pressure is back to normal. Never again will I use Pennzoil Platinum... haha.

We replaced belts, the O-ring for the pickup (again, thanks for the link), and transmission fluid.

I hope to keep driving this truck for another 100k.

If something changes, I'll post back, but I'm keeping my fingers crossed that this did the trick.