1999 Dodge Dakota Intermittant Oil Pressure Drop

UHCLEM

MEMBER
1999 DODGE DAKOTA
6 CYL
2WD
AUTOMATIC
76,000 MILES

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?

3 Replies

CARADIODOC

MECHANIC
33,743 POSTS

So if I understand correctly, the mechanical gauge drops also when the dash gauge drops. That would rule out the sending unit which has been known to cause this symptom.

Based on your comment about losing pressure when increasing engine speed, I'd start by looking for debris blocking the oil pump pickup screen. While the oil pan is off, inspect the pump's pickup tube too.

A spinning engine bearing will cause this symptom but let's not approach that yet unless no other cause is found.

Caradiodoc