Short vs long term fix for low oil pressure on 6.2

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

B-train

Full Access Member
Joined
Sep 12, 2022
Posts
2,311
Reaction score
4,001
The front diff comes out with 4 bolts/nuts and then 12 for the axles. It's so easy to remove ans gain more space it's silly to not remove it. You'll need a jack or extra hands to R&R. It can be done by oneself, but it can be squirrelly and punch you in the face if not balanced right.
 
OP
OP
W

WeekenderNutJob

TYF Newbie
Joined
Dec 27, 2022
Posts
22
Reaction score
26
@weekendernutjob I don't know if this applies to the AWD model but I heard that you can remove the oil pan without dropping the front diff entirely
Yes, I found a video that showed dropping it part of the way but not actually having to pull the entire differential. Still a big job but on my shortlist.
My 2008 6.2L will run a minimum of 20 on the guage at idle. This moves a little depending on temp, but it never goes below that. My 2007 Denali would actually have lifter rattle on a warm restart before I did the oil pickup o-ring and top plate o-rings. That was hot summer temps though, so everything was HOT and thin. I learned as I went and that was the last straw that made me learn, dig, and repair.
No funny noises, just drop down to 5-10 psi on the gauge when idling at a light and warm. No warning lights or messages. I guess dropping the pan to do the pickup o-ring is on my shortlist, and then the top side o-rings in the lifter valley are next if that does not do it....and hopefully, I don't have to do the oil pump...that seems like a PITA. The good thing is a flush at least helped....
 

B-train

Full Access Member
Joined
Sep 12, 2022
Posts
2,311
Reaction score
4,001
If you are short on time and/or help, I'd go after the cover plate o-rings. It only takes a couple hours ans you don't need a second set of hands to do. There are 8 spots for oil pressure to bleed off from vs 1 potentially cracked o-ring in a cavity. In my experiences, those were the biggest culprit in loss of oil pressure. About $100 in parts and you're back in business
 

Fubar0715

Scott
Supporting Member
Joined
Jun 13, 2020
Posts
667
Reaction score
1,351
Location
Southern New Hampshire
@weekendernutjob I don't know if this applies to the AWD model but I heard that you can remove the oil pan without dropping the front diff entirely
That was how I did mine - unbolted from the frame and supported with a jack to get some clearance. Was not horrible to get out of the way!
 

Fubar0715

Scott
Supporting Member
Joined
Jun 13, 2020
Posts
667
Reaction score
1,351
Location
Southern New Hampshire
There is a "test" for the pump O ring issue...
Add 2 extra quarts of oil to the engine and idle it on a downhill grade.. not extreme though.
If you oil pressure is better, than it's prob the oil pump p/u tube O Ring...
But don't keep running the extra oil... that's a big NO NO
At least you'll know ... I don't really know it this is a 100% diagnosis but it's easy;cheap and
worth a shot...
The advice on the lifter valley O rings is also solid... they will puke oil pressure if not
sealing to the valley plate correctly.. It's pretty easy to do as well
I read this too as a way to diagnosis however, since I had a leak already on the gasket and block plate - just made sense to pull the pan and replace the o-ring.
 
OP
OP
W

WeekenderNutJob

TYF Newbie
Joined
Dec 27, 2022
Posts
22
Reaction score
26
If you are short on time and/or help, I'd go after the cover plate o-rings. It only takes a couple hours ans you don't need a second set of hands to do. There are 8 spots for oil pressure to bleed off from vs 1 potentially cracked o-ring in a cavity. In my experiences, those were the biggest culprit in loss of oil pressure. About $100 in parts and you're back in business
Yes, I think I am going to do this first as its quicker and may save me the work on the bottom end.
 

petethepug

Michael
Joined
May 4, 2016
Posts
3,089
Reaction score
3,399
Location
SoCal
After the pick up tube, change the valley cover gasket and oil pressure sensor because it’s right there. This is my 09 at about 150k clicks.

916EAE5A-AF29-44B8-B4A0-248DA5E349F4.jpegEBF256E6-F028-479E-8D59-9F08CD57C2D0.jpeg

 

Forum statistics

Threads
132,697
Posts
1,872,717
Members
97,508
Latest member
nwalk7800
Top