MYSTERY DROP IN OIL PRESSURE AT IDLE

[Steve P.]

Yes, I tried a manual gauge.  There was one on it when I bought the car (which I removed).  It agreed with the factory one, and they were hooked up differently i.e. factory one to a sending unit, the manual one to a plastic tube.

You say: (It agreed with the factory one). Was that hot and cold? Was that before you noticed a problem??

Like I said, I would want to know exactly what a KNOWN GOOD manual gauge says at HOT idle. (Before the oil pump change and after)..

If you are not taking notes on your motor you will never really be able to properly diagnose anything while it's happening.

Your mechanic should have made note about what the pressure was before and after the change. If for nothing else but his own experience.

[histoy]

You initially stated that you had replaced everything except the oil pump, which has now been replaced, but you have the same results.  The problem sounds very similar to an engine that I once had.  One day it started reading 0 - 5lbs. at idle with a top oil pressure of only 25 lbs.  The engine never made noise, however I replaced the oil pump twice before determining that the cam bearings had worn out.  If you didn't replace the cam bearings, that may be your problem.

[Highway by the Sea]

I intend to get a compression test done on it soon, and have the motor gone through by a good mechanic.  I appreciate everyone's input!