QuestionQUESTION: The oil gauge shows normal pressure when I turn the key on without starting the motor. Is this a method of gauge testing or do I have a gauge or sensor problem?
ANSWER: I'll need the year, make, model and engine size in order to answer your question.
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QUESTION: 2001, grand cherokee, limited, 4.0L
AnswerHonestly it could be either. And it could also be a wiring concern. A fair amount of testing would need to be done at a competent repair shop to find the actual problem. But for now there is one test test that you can perform to check the gauge operation. The procedure that follows puts the instrument dluster into self=diagnostic mode and tests the gauges as well as the displays.
1 Begin the test with the ignition switch in the Off position.
2 Depress the odometer/trip odometer switch button.
3 While still holding the odometer/trip odometer switch button depressed, turn the ignition
switch to the On position, but do not start the engine.
4 Release the odometer/trip odometer switch button.
5 Monitor the operation of the suspect gauge(s) and/or indicator lamp(s).
6 The instrument cluster will automatically exit the self-diagnostic mode and return to normal
operation at the completion of the test, if the ignition switch is turned to the Off position
during the test, or if a vehicle speed message indicating that the vehicle is moving is
received from the PCM over the PCI data bus during the test.
7 Go back to Step 1 to repeat the test, if required.
You should also try unplugging the oil pressure sensor, on the right side of the engine near the oil filter, and observe the gauge. If it drops to 0 then you'll know that the sensor is sticking. If it stays at the level you indicated and the cluster tests passed you'll need to have additional diagnotics performed.
