Hi Guys, I'm having a low oil pressure issue with the H2 2008 with 86,000 km on the engine.
I did an oil change 2 days ago using 5w 30 Royal Purple synthetic oil.
At idle the oil pressure needle is now lower than before. It's now between 1/4 and the 275, the needle is just before the ''2'' in the number 275 when the engine is up to temperature .When driving the needle is at half mark 275,on the 7. This is my first winter with the Hummer so I'm not sure what to the readings should be.

Last year Fall I used Quake State synthetic 5W-30 and did not see such a drastic drop in oil pressure as I've seen with this Royal Purple.

 

Ok, not to be offending, but are you sure you put enough oil in?
I have had experiences also where a different oil wouldnt give me the same pressure in my Vette's LS.... so I would say it could be possible in the H2s LQ.

Also, you might have a bad sender/sensor.
And it also might be a bad gauge.
Also, there might be a leak or the cap might not be on tight enough to pressurize.
Also might be a bad pump, or pickup

I say look at the little stuff first, then go bigger.

 

I did check the oil level and it's about 5mm above the hatched full mark on the dip stick.

Notsurewhatusernameyet,,what's your oil pressure reading on your H2??

 

Posted Today, 09:54 AM
I have the exact same reading on the oil pressure gauge on my 08 H2 since i got it on 2008. I'm using Mobil 1 Synthetic with AC Delco Duraguard PF48 oil filter and i never had any issues with it.

As per owner's manual:

Oil Pressure Gage
The oil pressure gage shows the engine oil pressure
in psi (pounds per square inch) when the engine
is running. Canadian vehicles indicate pressure
in kPa (kilopascals).

Oil pressure may vary with engine speed, outside
temperature and oil viscosity, but readings above the
low pressure zone indicate the normal operating range.
When the oil pressure reaches the low pressure zone,
the OIL PRESSURE LOW STOP ENGINE message
will appear in the Driver Information Center (DIC).
See DIC Warnings and Messages on page 3-56 and
Engine Oil on page 5-13 for more information.
A reading in the low pressure zone may be caused by a
dangerously low oil level or some other problem causing
low oil pressure. Check your oil as soon as possible.

CAUTION:
Do not keep driving if the oil pressure is low.
If you do, your engine can become so hot that
it catches fire. You or others could be burned.
Check your oil as soon as possible and have
your vehicle serviced.
Notice: Lack of proper engine oil maintenance may
damage the engine. The repairs would not be covered
by your warranty. Always follow the maintenance
schedule in this manual for changing engine oil.

Hope these help!

 

Glad you read my reply on the other forum.

 

Anything to help the other guy's that is stressing over his 2008 H2 Hummer.
Thanks for posting it.

The funny thing is, there is $60.00 of 5 Day Old Royal Purple oil in the Hummer and I thinking REAL HARD on replacing the oil just about now.

 

In my opinion, even if you use any brand of synthetic oil, i don't think it will change the reading on the oil pressure gauge. But you can always try to see which one works best.

 

My first oil change to the Hummer was last year April I was getting higher oil pressure reading with a semi synthetic Quaker State 5W 30 and Lucas oil treatment. The oil pressure needle was shy of the 12 O'clock position during the summer months but was dropping gradually as the oil thinned itself out around fall.
September, 6 months later, I did another oil change and used a Synthetic Penzoil 5W 30 without the Lucas treatment I would not recommend this oil as it thinned out after one month.
March, 7 months later, I did another oil change using a full Synthetic 5W 30 Royal Purple, 3 days of using this oil and it's almost like it thinned itself out and lost it's purple colour this is where my oil pressure needle is to date.
Take a look at the video below.
This was taken when I first got the H2 back in April 2013,and before my first oil change.
This is where the needle sits when the engine is hot and ready using Royal Purple oil. Or after months of use with other oils

 

My 2008 H2 6.2 engine has always read low oil pressure.
It now has about 64,000 miles and no problems.

 

Question: If I wanted to replace the bad lifters on this 2008 6.2 Litre V8 engine, would I have to remove the heads in order to get access to the lifters?