New to the LS world. Having an oil pressure issue and I’ll do my best to explain.

Bought the truck about a month ago. Has 3600 miles on a complete rebuild with proof from previous owner. 6.0ls with 862 Heads and a BTR stage 3 cam kit. Vats delete.

When I bought the truck it had 40lbs at idle and 60ish lbs at 2200rpm. A week later the oil pressure dropped to 5lbs at idle and 20ish lbs at 2200rpm. It had a standard brand Oil Pressure Sensor so I swapped it out for an AC Delco and no change. Pulled the pan and replaced the oil pickup o-ring, no change. Ran engine flush and changed the oil, pressure went up to 20lbs at idle and 30lbs at 2200rpm. The next day went back to 5lbs at idle and 20ish lbs at 2200rpm. I also installed an analog oil pressure gauge just to check the cluster and it reads the same.

This is my first LS so am I missing something or is a new oil pump with 3600 miles on it possibly bad?

 

What oil weight are you running? What oil pump? Have you pulled the filter and cut it open yet?

 

10w30. Stock spec Melling oil pump. I had the oil changed after running the engine flush but didn’t cut the filter open. When I pulled the pan 2 days ago to do the pickup o-ring everything looked good.

 

Any chance you pinched the o-ring putting it together? You could put in an extra qt or 2, and jack up the rear end, start it and let it idle. The oil should cover the pickup tube o-ring and seal it if it was sucking air. Just idle though, dont go crazy.

 

I am sure. It had good pressure for 3mths. Then suddenly didn’t. Then I replaced the oring and nothing changed. I can try that trick and see what happens though.

 

So a week after you bought the truck the oil pressure dropped off like a rock? After how many miles? Did you do anything before the drop like change the oil or install something that could affect it? Honestly it sounds like the sawdust they put in the oil to thicken it up wore out. . . . All jokes aside I would add checking the cam bearings to see if one shifted causing your loss of pressure.

 

Trust me I thought about the sawdust too. But when I pulled the pan it was clean. Lol

I didn’t do anything to it. Drove it home 200 miles no issues. Drove to work for a week then boom.

 

Do you have the complete build parts list?

 

I don’t. He showed me all the pics/videos of it being pulled and build progress. I seen the receipts for the cam kit but that was it. Some drag racer down in New Pittsburgh, TN built and tuned it.

 

After the build, before exhaust. Oil pressure was solid. See video.

 

Thought! This truck is a 2000 2500 and has an oil cooler. Could a clogged or bad oil cooler cause the issue? Motor only has 3600 but truck has 274k and it’s the stock oil cooler to my knowledge.