Thread: oil pressure needle irractic

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I cut the oil filter apart, nothing to say its abnormal, no metal or bearing material. Drained the oil, thinking may that the oil was diluted with water. all seemed good , still have not fired it up again, will try another gauge tomorrow, let you know how things turn out.

When you get the gauge disconnected, fire the engine up and bleed the line into a can, and get all the bubbles out. Air can make a gauge do some weird things.

If your gauge is fine, then this oil pressure pulsing could be the symptoms of a multitude of possible reasons, including but not limited to: bent distributor shaft, improperly installed distributor, non-concentric distributor gear (unlikely), bent oil pump shaft, debris blocking the closure of the oil pump's internal bypass port (piston stuck), cracked pickup tube, partially blocked pickup tube, etc.

But, I suggest changing your oil filter. Have you run the engine since cutting the first filter apart? I've seen this before where the anti-drainback flapper in an oil filter was causing the exact same symptoms (anti drainback flapper was damaged during manufacture), and I'll bet that installing a new oil filter will eliminate the problem.

Paul

P.S: If you have an orange Fram filter, remove it and replacie it with a better filter, perhaps a FoMoCo FL1A, available at Wal-Mart for cheap. I suggest that you do this even if the newly installed orange Fram filter has eleminated the oil pressure fluctuation.