My brother-in-law has a 2004 Yukon with the 5.3 (I'm assuming it's the LM7). Low oil pressure at times and has heard some ticking from the valve cover area (lifters?). He has basically parked it because he doesn't want to damage it (an LQ4 in the family sadly got damaged from an oil pump going out). I'm assuming the oil pump is going out... if that is the case, is there a certain oil pump brand we should look for? Any other tips? I think family is going to try and help him replace it. Thanks!
5.3 Oil Pump
- Thread starter Blang
- Start date
Check to see if the oil pump pickup o-ring is bad, add 2 extra quarts of oil and jack the back end of vehicle up. This should have oil over the pickup tube o-ring. If the pressure increases you have found your issue. Pretty common issue. Gauge clusters of that era are know issues as well. verify with manual gauge.
This is great advice!
This is a comon problem, usually worse when cold, as the oil is thick and the pump sucks air in around the oil pickup o-ring.
Easier to drop pan and replace the o-ring if it's 2wd.
I think around 150k miles, but I'm not absolutely certain.
Low pressure... I think he said the needle barely moves up. Seems I see oil pressure normally between 30 and 60 if I'm thinking right.
Thanks! Good idea. So if it's just the o-ring, is it worth replacing the oil pump if you gotta dig into it that far? It is 4x4/AWD so the front diff is in the way of course.
It's not unheard of for the Pressure Regulator Valve in the Oil Pump to stick open. I would do the overfill trick first to eliminate the O-ring as the cause.
I use OE pumps, I've never considered the Melling LSx offerings an upgrade.
I use OE pumps, I've never considered the Melling LSx offerings an upgrade.
Thanks! I'll pass that info along. If it's just the o-ring is it worth replacing the oil pump while the convenient chance is there?
It depends on what the issue is. If it just the o-ring and pressure was back to normal after the test, I would not replace it. Your call, I assume the vehicle is getting up there in miles?
Just checked. Looks like it's pushing 180k miles. My father-in-law has been pretty sour on LS engines lately because of oil pump issues that he's observed. Are the large majority of the oil pump related issues mainly just the o-ring?
The oil pump in the LS is not in the pan like other engines. It is part of the front of the engine.
They rarely fail and I see no reason to replace one if the oil pick up orings is what the problem is.
They rarely fail and I see no reason to replace one if the oil pick up orings is what the problem is.
What Chris said. You can't replace the oil pump by just dropping the pan. Have to pull the harmonic balancer off of the crankshaft and covers off the front of the engine if I remember correctly.
I had an oil pressure problem with a 2005 6.0 and unfortunately a new o-ring and oil pump did nothing to fix it. Ended up selling the truck as is.
I had an oil pressure problem with a 2005 6.0 and unfortunately a new o-ring and oil pump did nothing to fix it. Ended up selling the truck as is.
No idea what the oil pressure problem was?
Gen III engine do not have a pressure relief valve in the oil pan.
I'm not answering for RedZ, However......Cam Bearing wear is more common on LSx engines than most know, I see it quite a bit on Company trucks & vans that idle excessively.
Yep, that was my guess too. That or main bearing wear. It was a company truck from my wife's landscaping business that had already lost enough money that I was over it. Getting rid of that truck and collecting the bond from the state were the last two things that remained from that business. 10 years later still waiting on the bond. Drawback from living in a third world state like Nevada.
