Oil pressure 6.2

Grumpy Bear · August 20, 2018

I wanted to make sure of my facts before I weighed in so we went for a 150 mile jaunt. Not a particularly hot day, Mid 70's. Dead cold high idle pressure 28 psi on a scan gauge. Fully warmed up with oil temp over 205 F 24 psi =/- 2. Hot idle 560 rpm 20-22 psi. Hot higher speed (2000 rpm) 28 psi. Over 3,000 rpm variable from 30 to 52 nearly linear with rpm. Same numbers I have logged for 100 F days.

On the dash gauge we get a different story. Cold idle 42, Hot down the road 38. Hot idle 32 and nailed to the wall 80+. Point is the dash gauge and actuals are not even close. The dash gauge is a 'feel good' idiot meter.

Yes my motor is the 4.3 not the 6.2 BUT they share the same oil system strategy. The call out of this little motor is 5W30 and I run 0W20. I've tired 10W40 and it makes zero difference to the oil pressures when warmed up. A bit higher when cold. Because??? Unlike your grandfathers small block which dumped excess oil pressure to the pan after the pump but before the oil galley these critters dump the excess at the end of the circuit and use a variable displacement pump system.

On ‎8‎/‎16‎/‎2018 at 5:36 PM, ltzsilverado said:

I just looked the information up on all data and min. Oil pressure is 22psig at 1000 rpm , 30 psig at 2000

check and check. The numbers it should read with a Tech II or equivalent OBDII tool.

Almost every one of these I've seen will hold the dash gauge roughly 40 psi in cruise and over 35 dash idle. You gauge would give me pause and it could be literally anything. Sending unit, Screen, Gauge and/or worse. Have it checked out before the warranty expires. Devils in the details. Have a nice day.

CadillacLuke24 · August 24, 2018

On 8/20/2018 at 1:14 PM, Grumpy Bear said:

Almost every one of these I've seen will hold the dash gauge roughly 40 psi in cruise and over 35 dash idle.

That's where Clyde lives. When I stomp on it stage 2 kicks in and I damn near hit 80, but otherwise he hangs out between 35 and 40.

It would be a good idea to check it out. You've got nothing to lose man.

roblp · August 4, 2020

He everyone. I have a 2015 GMC Denali with 6.2. and for my first 30 days, I love it! but, At 110 k I just lost the engine, I purchased it at 108K. Was cruising down highway at around 65 when all of a sudden the engine wanted to die, would not tach up, even when trying to give it gas is continued to decelerate, I thought for sure it was the fuel pump. I watched the oil pressure drop to almost nothing when I pulled over on side of road. It would not start even though it would crank. Mechanic said engine is toasted. I just purchased 30 days ago from small car dealer. It will start but the motor knocks, squeaks and will not idle of course. The only info I have about the history is it was extremely well maintained, oil changes every 5-6 k. It had a code in the computer history saying it had a problem with "crankshaft sensor" recently. Dealer had know idea what this was and said to me don't worry, I will stand by engine if something happens. It did have the occasional acceleration smoothness problem that we all experience with the V4/8 fuel system, I understood that the hesitation does have something to do with the crank sensor issue". I also heard that it had one broken valve spring that was replaced a month before I purchased. Can someone please help with what you think happened here? I'm absolutely demanding a new GM crate engine to be put in, love the vehicle. need advise on what to do here. Bob from Ma.

truckguy82 · August 4, 2020

3 hours ago, roblp said:

He everyone. I have a 2015 GMC Denali with 6.2. and for my first 30 days, I love it! but, At 110 k I just lost the engine, I purchased it at 108K. Was cruising down highway at around 65 when all of a sudden the engine wanted to die, would not tach up, even when trying to give it gas is continued to decelerate, I thought for sure it was the fuel pump. I watched the oil pressure drop to almost nothing when I pulled over on side of road. It would not start even though it would crank. Mechanic said engine is toasted. I just purchased 30 days ago from small car dealer. It will start but the motor knocks, squeaks and will not idle of course. The only info I have about the history is it was extremely well maintained, oil changes every 5-6 k. It had a code in the computer history saying it had a problem with "crankshaft sensor" recently. Dealer had know idea what this was and said to me don't worry, I will stand by engine if something happens. It did have the occasional acceleration smoothness problem that we all experience with the V4/8 fuel system, I understood that the hesitation does have something to do with the crank sensor issue". I also heard that it had one broken valve spring that was replaced a month before I purchased. Can someone please help with what you think happened here? I'm absolutely demanding a new GM crate engine to be put in, love the vehicle. need advise on what to do here. Bob from Ma.

make a new thread

not enough info either, did the oil end up on the ground?

I’d ask the mechanic what is wrong with the motor, he must know if he said it needs to be replaced

JimCost2014 · August 4, 2020

7 hours ago, roblp said:

It did have the occasional acceleration smoothness problem that we all experience with the V4/8 fuel system, I understood that the hesitation does have something to do with the crank sensor issue".

This is my 3rd K2, have never had an issue with transition of the DOD.

Kind of sounds like it had a major failure, and was not fixed properly.