I have an 87 Porsche 930. Today I noticed that my oil pressure gauge is telling me that I have no pressure. The gauge just sits at the same place it is when the ignition is in auxillary. It does not move a smidge no matter how much I ride the accellerator. Oil level is just fine. Nothing has changed since I drove it Thursday. Is this just a bad sending unit or gauge, or is this a problem in the motor? I'm quite new to these things, and I'm not sure how worried I should be.