I'm thinking that I'm either have problems with the Sensor or the gauge. Cold start up I've got 40psi cruising 50-60psi stays this way for about 30 minutes of driving, then the gauge starts to read higher, sometimes even pegging the gauge. Then it starts to drop slowly and responds very little to rpm. It will drop until it eventually bottoms out. I was 15 min. from home and decided to chance it. (Worst thing that can happen is me ending up with a forged motor right? lol) I drove home and no noises, no loss of power, nothing. Oil smells good, level is good, Mobil 1 5w30 with 2000 mi. since the oil change. Happened a couple more times since then with same results. Could it be 30 min. before the top of the motor is heat soaked?

I would feel certain that it was the sensor except that if it read 0psi, wouldn't I get an alarm or message on DIC? I'v got no lights, no codes, zippo. Just a gauge sitting on 0. Could it be the gauge going out in the cluster?

Also, is there anywhere to hook up a manual gauge to verify? I'd have to be able to drive around with it hooked up. The sensor location looks like I'd have to pull the manifold to get to it.

 

It could be the servo motor. Mine went bad in my oil pressure guage. If it is, it could be covered under the extended warranty GM service bulletin.

 

if you have less than 70k miles it will be warrantied, other wise you can buy a stepper motor off of ebay and sodder it in or replace your entire cluster.

 

It's a TSB? anyone got a number? I've got 64000 on the clock, hope that's it.

 

Through some google searches I found this, but no description. Do we have a tech here that could get the full text?
#03-08-49-009 SMU - Revised Engine Oil Pressure Gage Inaccurate or Inoperative Diagnostic Information - (Jun 24, 2003)

Also Found this
03-08-49-020 NOV 03 Instruments - Gauges Inoperative