Oil pressure dropping

[Rocket Man]

I'm in exactly the same situation as Joel! Just heard from the shop that replacing the o-ring did not bring the pressure up. They are putting in an oil pump now. I hate paying someone to do something I can do but I have no time and I'm in the middle of home improvements right now and need the truck.

You gotta do what you gotta do.

 

[Musicars]

From my understanding it's more for the NNBS which run at a lower pressure stock. I believe melling has info on their site. There's also a high pressure one I believe. I went with the normal one on mine at 150,000 miles. It runs 45 at idle and 60 when revs are up.

Melling has several different ones for this motor. I assumed that the HV made up a bit for the increased bearing clearances of a worn motor. I didn't really think 170,000 was that worn. If I could get around 45 psi at idle I would be ecstatic. Thanks for that info.

 

[Musicars]

I'm in exactly the same situation as Joel! Just heard from the shop that replacing the o-ring did not bring the pressure up. They are putting in an oil pump now. I hate paying someone to do something I can do but I have no time and I'm in the middle of home improvements right now and need the truck.

I hope you report back with how it turns out for you.

 

[sam05]

I will...waiting by the phone to find out if I'm picking up the truck tonight or bumming a ride home (again).

 

[sam05]

Ok. So shop with best reviews in town has replaced oil pressure switch, oil pump (Melling High Volume 295HV), Oil pick up tube o-ring and says it still doesn't have enough oil pressure. He's had the truck since Wednesday night. What else can it be guys? It already has a new rear main seal from a month ago when I had to replace the flex plate.

 

[Rocket Man]

Ok. So shop with best reviews in town has replaced oil pressure switch, oil pump (Melling High Volume 295HV), Oil pick up tube o-ring and says it still doesn't have enough oil pressure. He's had the truck since Wednesday night. What else can it be guys? It already has a new rear main seal from a month ago when I had to replace the flex plate.

If the shop has checked the pressure with a mechanical gauge to make sure the pressure is indeed low and it's not just the gauge, then that motor needs a rebuild because it would mean the bearings are worn.

 

[sam05]

How do we verify that? The motor runs great and doesn't make any ticking noises at all.

 

[Rocket Man]

How do we verify that? The motor runs great and doesn't make any ticking noises at all.

The mechanical gauge attaches where the oil pressure sensor is installed. Any reputable shop knows to do that though when they're chasing low oil pressure so see if they've done it. What all have they done to verify pressure? And why did you taking it to the shop in the first place?

 

[Musicars]

Ok. So shop with best reviews in town has replaced oil pressure switch, oil pump (Melling High Volume 295HV), Oil pick up tube o-ring and says it still doesn't have enough oil pressure. He's had the truck since Wednesday night. What else can it be guys? It already has a new rear main seal from a month ago when I had to replace the flex plate.

Sorry, your having issues too. I was rooting for you regarding the pump. Today I swapped clusters with one I got from an '05 Denali and got the exact same low pressure reading. So, I doubt I have two clusters with bad pressure gauges. I'm looking at the pump now on mine.

I'm lucky I didn't get rid of my old mini-van so I have something to drive in the meantime. It rides like an old buckboard due to a bad rear air suspension but it runs.

 

[sam05]

The gauge now reads the same as it did before I took it in but he says that’s because my oil pressure sensor was bad and everything is right now. Does anyone have guidance on where the gauge should read when warmed up? A different shop told me to put 10W40 in it instead of the 5W30 this shop put in?