IMPORTANT: The Chronicles of Low Oil Pressure by 07burb

[Gilla]

I'm in the same boat. 07 Suburban, replaced everything. Pickup o ring twice with the green o ring. SO....why does the tube come with a redish o ring? Mine holds 10 to 12 lbs at hot idle 35 ish at cold. I'm driving it. My 350 had 12 ish lbs and ran fine. Pressure goes up to 40 plus quite easily when ya touch the gas. I'm gonna try one more time. I'm gonna put a red oring and new tube in it. if it stays the same then I'll drive it untill it drops. Runs great as is, no issues. As far as the bearing clearances go, why did it have great pressure before then turn crappy? BTW... I am running a mechanical oil pressure gauge from the position of the sending unit. Yes..filter removed. Melling 295HV comes with green and black oring. I'll try the red, only gonna cost a couple gaskets and effort. When I can get to it, I will post back here the difference, If any.

 

[Fless]

Which engine does it have? (What's the RPO code?)

 

[j91z28d1]

I'm in the same boat. 07 Suburban, replaced everything. Pickup o ring twice with the green o ring. SO....why does the tube come with a redish o ring? Mine holds 10 to 12 lbs at hot idle 35 ish at cold. I'm driving it. My 350 had 12 ish lbs and ran fine. Pressure goes up to 40 plus quite easily when ya touch the gas. I'm gonna try one more time. I'm gonna put a red oring and new tube in it. if it stays the same then I'll drive it untill it drops. Runs great as is, no issues. As far as the bearing clearances go, why did it have great pressure before then turn crappy? BTW... I am running a mechanical oil pressure gauge from the position of the sending unit. Yes..filter removed. Melling 295HV comes with green and black oring. I'll try the red, only gonna cost a couple gaskets and effort. When I can get to it, I will post back here the difference, If any.

you have the high volume pump and it still has low pressure. huh that's interesting.

usually that's the cover.

I doubt throwing a bunch of different o rings at is will help but let us know how it goes.

there's a video somewhere of a spun cam bearing, that's about all they makes sense to me if you have a high volume pump, main and rod bearings look good and you have low pressure. if you have the pan off, spend some time looking up at the cam and see if you see a bearing moved but also 12psi hot idle is above min spec. it's something like 7psi hot at 1000psi. if you're not doing something like heavy towing or racing it. it will probably out live the truck at 12psi idle.

 

[Geotrash]

I'm in the same boat. 07 Suburban, replaced everything. Pickup o ring twice with the green o ring. SO....why does the tube come with a redish o ring? Mine holds 10 to 12 lbs at hot idle 35 ish at cold. I'm driving it. My 350 had 12 ish lbs and ran fine. Pressure goes up to 40 plus quite easily when ya touch the gas. I'm gonna try one more time. I'm gonna put a red oring and new tube in it. if it stays the same then I'll drive it untill it drops. Runs great as is, no issues. As far as the bearing clearances go, why did it have great pressure before then turn crappy? BTW... I am running a mechanical oil pressure gauge from the position of the sending unit. Yes..filter removed. Melling 295HV comes with green and black oring. I'll try the red, only gonna cost a couple gaskets and effort. When I can get to it, I will post back here the difference, If any.

Different pump manufacturers use a different color of material for the same thickness o-ring. You always want the thicker of the two that come with the pump. If it's a Melling pump, then the green o-ring is the thicker (and correct) o-ring for a truck engine.

 

[j91z28d1]

I think this was the video.