Question: 1997 JEEP GRAND CHEROKEE V8 (4WD) OIL PRESSURE GAUGE GOES TO ZERO EVEN WHEN FULL
OF OIL. WILL OCCASIONALLY REVIVE TO SHOW NORMAL PRESSURE BUT WILL GO BACK TO
ZERO ON NEXT IDLE AND USUALLY STAY THERE. IS IT OIL PUMP OR 'SENDING UNIT' OR
Answer: The oil pressure gauge has nothing to do with the oil level. That would be an oil level waning. Usually low oil pressure will cause an engine noise. If you do not hear any, then i would suspect the oil pressure sending unit, or sometimes called a switch.