So I have an 03 H2 that I've had 2 years now. It's ran like a champ the entire time I've owned it until a couple of days ago. It started up and drove fine all morning while running errands. I stopped by the house to use the restroom and when I came out to run one more errand, I fired it up and was greeted with a low oil pressure message and 0 psi on the gauge. So I shut it down and checked the oil which was full as usual.Thinking it was the oil sender going bad I fired it back up and it started ticking. So I shut off and called a tow truck to carry it back over to where I store it. I rolled it down the driveway and had to start it up and back it up to get it closer to the curb so it be easier to load. Then the oil pressure came up to its normal idle range (40-45 psi) and it immediately stopped ticking. So I cancelled the tow and drove it back across town and it did great oil pressure was normal while driving 45-55psi. Ive driven it a few times since and no hiccups at all. Any idea as to why that happened? I'm running that mobil 1 5w30 SUV synthetic oil and a wix oil filter. Thanks for any insight.

 

Stepper motor in the dash could be bad , but that would not explain the ticking noise, possible oil pick up tube O ring getting bad. How many miles on it?

 

[QUOTE=calif phil;406722]
I was thinking it was something in the dash until it started to tick. I'll have to look into the O ring on the pick up tube. It has 169k miles on it.

 

You can overfill the crankcase with 2-3 more qts of oil, that will submerge the oil pick up tube o-ring as a test, if it starts with good oil pressure, then you found your problem. it helps to raise the rear of the vehicle or park backwards on a slope.

 

Don't know how many miles you have ..But Taking a wild guess it could be a Clogged oil pump screen or some debris that got into the pick up and then cleared. Or something to do with the oil filter by pass or oil filter assembly in that area. Sounds like you lost oil pressure for sure if you heard the Lifters singing.

A few years back I lost oil pressure in my 502 in my 65 Vette. Turned out the distributer dive tang sheared the oil pump slot off. It was Clang Clang city. You have an LS motor in there so I'm not sure how the pump system is set up in the LS. Not being an LS expert I wouldn't know how that system works but I think the oil pump is driven off the front on the motor.

I know we have some super duper HUMMER H2 LS experts here and lets see what they have to say. Me......I would go with something that might have
temporarily blocked the pick up screen But Then again WTFDIK....

 

[QUOTE=Mark R;406859]
[QUOTE=calif phil;406849]
I'm gone change the oil this weekend and see if anything debris wise is in it. I appreciate all of the help guys. I drove it again tonight, and it drove like beast as usual.

 

Maybe add a can of Rislone engine flush before the oil change.

 

[QUOTE=calif phil;406870]
Good idea, I'll do that. Thanks again