Mechanics

GMC JIMMY OIL PRESSURE PROBLEM

1999 GMC Jimmy • 6 cylinder 4WD Automatic • 180,000 miles

When I start my 1999 GMC Jimmy the oil pressure gauge spikes up over 80 and stays there. Oil is fine and recently changed. How do I tell if I have a bad oil pump or oil pressure snding unit or a switch or other malfunction?
Avatar
Darrenbrandt
April 20, 2011.




Best place to start is by measuring the pressure with a mechanical gauge to see what you really have. I'd suspect the sending unit first but for a quick check, unplug the connector from the sending unit. If the gauge stays at maximum, that wire is grounded somewhere.

Caradiodoc
Apr 21, 2011.
Checking the pressure with a mechanical gauge is a good idea but with the labor time involved to do that, it may be cheaper and easier to just throw a new sender on it. It's cheaper than the labor time.

Wrenchtech
Apr 21, 2011.
Is the oil pressure sending unit easy to replace and if so where is it located at?

Tiny
Darrenbrandt
Apr 21, 2011.
That one should be in the back of the engine, next to the distributor. It just threads in but you may need a special socket.

Wrenchtech
Apr 21, 2011.
I took off the air intake and the distributor off and got to the oil pressure sensor to find that it was unplugged. I plugged it back in and that fixed my problem. Thanks for your help.

Tiny
Darrenbrandt
Apr 24, 2011.
I wish they were all that simple.
AD

Wrenchtech
Apr 24, 2011.
No kidding. That choice isn't even on my dart board!

Caradiodoc
Apr 24, 2011.

AD