I did a search, about 5 or 6 pages back, and could not find anything like my issue.

While at a stop, at 600 rpms my stock gauge goes to zero, at 70 mph, 2,000 rpms, I get just under 20 lbs pressure, at 45 mph, 1500 rpms, it goes to about 10 lbs. I understand you basically need 10 lbs per 1000 rpms for a stock vehicle, so, pretty much I am good there.

I have not checked with a mechanical gauge yet, but I can tell you that the oil level is about half way through the hashed area of the dip stick. It is not burnt, but brown as expected, and due to be changed soon. The motor has less than 10,000 miles on it, with a fresh rebuild when we converted from a 5.3 to a 6.0.

There are no check engine lights, low pressure lights, no lights come on at all. I have not heard any knocking or pinging of any sort. When I hit the gas, the pressure rises, and does not fall off until I let off the gas. I have not held it to the floor, or hit the gas for a long distance for fear of damaging anything.

It may be as simple as a sensor, but I won't know for sure until I do a mech. check, or just replace it.

I just had shoulder surgery, so I am trying to get the B.S. out of the way first. Any other educated guesses out there?

 

Look at the oil when you drain it. Look for metal particles. Either you have a bad sender or guage, or the motor or oil pump is toast. I would check that oil ASAP. You should have 40-50 psi at 45 mph with a new motor.

 

From day one, of this motor, it's never been that high, so, maybe it's just the sender....

And yes, I have thought about cutting the filter apart when we do the oil change, thanks for the help.

 

Fortunately, I replaced my sensor just before my shoulder surgery. (torn labrum) I can't imagine doing this repair within 8 months of that. Lot's of work with ones' arms over the head. (I'm not sure if that's a problem for your situation, or not.) The procedure is a PITA and I basically had to perform it laying on top of my engine.

https://ls1tech.com/forums/general-m...ding-unit.html

If this is a complication for you, you might want to go with the mech gauge first, even though the sensor isn't that expensive.

 

mechanical guage is best anyway. eliminates the factory guage as a problem

 

Ok, with some help from a couple friends we did a complete oil change, four ball joints, back to stock air intake system, and temporarily installed a mechanical gauge, new pressure sensor.

It was weird, the new sensor made it worse. Did the oil change, not much difference. Installed the temporary mechanical gauge, 50lbs! So, we figure it's the stepper motor in the dash. At least I know it's nothing to do with the motor, or computer. I'll add a permanent liquid filled gauge when my shoulder heals.

Hope this helps someone else in the future.....

 

The same happened to me. These OPSU's are notorious for being garbage. Did you get the GM one?

Many of us went with aftermarket replacements and had to take them out to go with a GM sensor.

BTW - I believe the gauge is not a stepper motor. Your issue is probably with the sensor.

 

Yes, I went with a GM replacement. I'll look into the stepper motor issue. Just for info sake, it's a 2003 Av, if anyone knows for sure if it has stepper motors or not.

 

Yep, it has stepper motors;

 

What kinda oil? have you tried a thick{er} oil?

 

I swapped sensors during a cam swap and though I had done something wrong after the oil pressure was lower
Put a gm sensor back in and everything was normal
I'd try a mechanical gauge first, easiest way to tell if it's ok or not

 

I did ad a mech. gauge temporarily, to see what the pressure actually was. I will add a permanent one soon.

Odd thing is, the stepper gauge is starting to creep up to where it should be... slowly. At times it will go low, but not to the point it was a week ago.