Mechanics

03' OIL PRESSURE SLOWLY DROPPING

2003 Hummer H2

Engine Mechanical problem
2003 Hummer H2 V8 Four Wheel Drive Automatic 101000 miles

Hi, I have an 03' H2 Hummer with oil pressure prob. I recently replaced the oil pressure sensor and did not take care of the prob. The pressure will only drop when driving for an hour or so. I drove the car on the freeway for about 90 miles till I noticed my oil pressure gauge is at zero psi. I still drove another 10-15 miles before stopping and checking the oil level, but it was ok. No signs of engine knocking, vibrating, loosing power or even engine light or oil warning in my dash. When this prob happens and I shutt the engine off and wait for few minutes, the gauge would come back at a normal reading at 38-40psi at idle, but if you shut off the engine and start it right away, the gauge gets stuck to zero psi till it cools down a bit. Please help!
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Gluvshey09
March 18, 2010.




It would almost require a physical oil pressure test with a test gauge to validate. If the oil pressure is determined good, then it could be a faulty cluster. The sensor that was replaced, was it on the left rear of the engine, behind the intake and a bit difficult to get to?

Factoryjack
Mar 18, 2010.
The sensor replacement is an OEM from Hummer dealership. The oil pressure test was also performed and found good compression on it. Not so sure about the gauge it self if its good or not, but it seems to be reading ok till I drive it for about 80-100miles distance and the oil pressure level will slowly drop. Its so slow that you cant even tell without knowing where your pressure level should really be. So, today I drove the car again about 100 miles back and forth and couldnt even tell that my pressure was already down to 20psi idle and 30psi cruising speed without staring at it.

Yes, the sensor that was replaced is located in the left rear behind the intake and it is difficult to get to. Is there another sensor behind the engine? Any other suggestion? Please help!
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Tiny
Gluvshey09
Mar 18, 2010.

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