I have a 2001 Audi 2.8L and the oil Pressure gauge not working

SOURCE: temperature sensor audi a4

Possibly located at the back of the engine behind cylinder head, usually located in a small plastic hose block.

TL

SOURCE: 4.7 liter oil pressure gauge malfunctioning.

Check or replace the oil pressure sending unit.

SOURCE: how to replace the iol pressure sender on my audi

NON-FSI PETROL ENGINES,THE SENSOR SWITCH IS SCREWED INTO THE OIL FILTER HOUSING,REMOVE THE ENGINE TOP COVER.UNBOLT THE COOLANT EXPANSION TANK MOVE TO ONE SIDE .THERE NO NEED TO DISCONNECT COOLANT HOSES.AND DISCONNECT WIRING PLUG FROM SENSOR.UNSCREW SENSOR.....FSI ENGINES REMOVE THE INTAKE MANIFOLD TO GET AT SENSOR....DIESEL ENGINES THE OIL PRESSURE SENSOR IS SCREWED INTO THE OIL FILTER HOUSING ASWELL.PRISE OUT THE CAPS,UNDO THE NUTS AND REMOVE THE PLASTIC COVER ON TOP OF ENGINE.REMOVE THE INSULATION BENEATH COVER (WHERE FITTED).DISCONNECT WIRING PLUG FROM SENSOR AND UNSCREW......BE PREPARED FOR OIL SPILLAGE.. HAVE A NICE DAY!!

SOURCE: In my 1996 jeep grand cherokee the oil pressure

might want to check the ignition control (the key) did same to me but with volt gauge

SOURCE: on my 1999 chevy silverado the only gauges that

The stepping motors in the gauges go bad. Do a search on ebay for CHEVY SILVERADO INSTRUMENT CLUSTER for cheaper repair options, dealer costs $300.00