Faults:

I have 40,808 miles on my 2004 Jeep Grand Cherokee.. When I start engine the oil pressure gauge needle does not move. (It stays lying down on left side of gauge. After about 5 minutes it moves towards the top of gauge, then hovers back and forth between the bottom left, and top for another minute or two before settling down at approximately correct pressure (straight up). The pressure stays correct, until I shut off engine and then restart.

I solved this problem by replacing the Oil Pressure Sensor that controls the gauge. (MOPAR Part # 1-04868672AA) The sensor is inexpensive, located on the passenger side of the engine block, near the firewall, and screws into the side of engine (and you have to plug the electrical wire that connects it to the gauge back in of course).

General Comments:

Other than this problem, I am very happy with my Grand Cherokee.