The truck was in the shop for a tuneup: filters, plugs, plug wires, rotor, distributor cap and serpentine belt. Within less that a quarter mile, it lost all oil pressure. Gauge dropped to 0. Oil level was fine. I took the filler cap off t look for obvious obstructions, found none, put it back on and the pressure was fine again. Drove it a few blocks, and it dropped back to zero. Since then, The engine has been flushed, oil and filter has been changed, Sending unit checked out OK, pressure checked with a gauge to confirm behavior. It knocks when the gauge shows zero and runs fine when the gauge shows full pressure. Sometimes, the pressure drops with RPM increase and comes back briefly only when the truck is shut off and re-started. Any ideas?
Mar 8, 2010 at 2:08 AM