Low oil Pressure Warning on H2
 

Hi ,
I just changed for the second time my oil sending unit. It works now except I now get a low oil pressure warning all the time....intermittent and I hear the engine knocking....what is the problem....plenty of oil.
Do I have a bad oil pump or is some thing cloggeed. Please help.
Thank you for your time.

You need to remove the sender and hook up a mechanical oil pressure gauge and get the true oil pressure readings, then we can help with further diagnosis.

Hi Phil,
Thank you, I have contacted my mechanic and we will do the test you recommend. I also am going to drop oil pan and change the oil pump. There may be debris in the pan. Problem is you have to drop the transmission to get to oil pan. 9 hour on the mechanics books.
Do H2 hummers have these problems ? Is a new engine in my future or maybe just a valve job. 165,000 miles on a 2007.
I really enjoy this car.
Thoughts.
Joeybiff

A new oil pump should solve your problems. I doubt you need a valve job.

Hi ... I got replaced the oil pump a few days ago .
The mechanic did a simple trick to determine if the problem was the pump or the sending unit /gauge
park the truck in a very steep hill ,leave it overnight before start it . The oil will goes upfront and flood the pump .if the issue is with the O ring or pump it should work fine . If the issue is with SU or gauge then the low oil will still be there
(dont trust 100%this method) will give you an idea

in my case the pump was bad .. Cost me 1700 . The job included a new pump , new front cover gasket , new oil pan gasket and new water pump gasket
if you havent replaced the water pump this is the best time to do so also
I also notice this fixed a noise which I supposed was coming from the exhaust broken bolts . In guess it was the relief valve recycling.
I got a list of parts you need for the job in case you wanna do it yourself
btw ... the front differential should be removed to access the oil pan but this is not 100 % necessary. Search online . Is hard but to do but not impossible
good luck

Hi H2 Miami
Thank you for your reply. I did try and test the oil pressure everywhere and found out I was loosing oil pressure because of a spun crank bearing.
There were also multiple areas where there were leaks and low oil pressure (mechanically checked) at three other points on the engine.
So I bit the bullet and purchased a new engine from Jasper with oil fix upgrades and corrections that the left valve cover has.
I really enjoy this H2 I have it new and i just did not want to buy another car....with CA Emissions upgrades, headers and Cooling air system....I may have gain a couple of miles per gallon.

I pick it up on Friday...Thank you all for your input....168,000 miles of hard driving...It was time.
Thank you for the well wishes.

My Best.

Jasper makes good stuff. Let me.know how it ended
I invested heavy in this truck cause nothing else gets even close
i got 135k miles . Next step in a few more thousands is a rebuilt engine
may I ask how much was the engine

Hi H2 Miami,
1.The engine from Jasper was $3,748.00
2.The install kit was $464.00
3.Valve Cover LT $154.00

That's what you get from Jasper....then you can do engine upgrades for there..i.e. K&N Air Filter, headers Hyper Tech Programmer.
Then all the parts and labor of replacing an engine.

The total cost for me was over $9,000.

I let you know how it runs.

Like you said...."nothing else comes close"