STEP BY STEP-TEST AND FIX LOW OIL PRESSURE ON MY 2002 5.3L (1500 SILVERADO) WHY IS IT LOW? WHAT COULD IT BE? ELIMINATE THE POSSIBILITIES. START WITH THE EASY STUFF. WORK TO THE MORE DIFFICULT. WE LOOK AT OIL LEVEL, OIL PRESSURE SENDING UNIT, CHANGE VISCOSITY, CHECK FOR BEARING WEAR OR DAMAGE. WE EVEN COVER OTHER POTENTIAL CAUSES, BUT FINALLY SOLVE THE QUEST FOR PRESSURE MYSTERY.