Ok so when I first got my car the oil pressure at idle was sitting right at 20lbs and would go up a little while driving as expected but now when it warms up and sits at idle the oil pressure will drop down close to 0 and the check gauges light will come on but when I rev it up it will go up close 35lbs "which it has never done before".

The oil pump has been replaced, the rod/main bearings have also been replaced. I'm thinking its a faulty Sending unit or something but it has gotten me worried because I do not want anything to happen to the motor. It just doesnt make any sense at all. I have full synthetic oil in it so that could be part of the reason for low oil pressure because it's so thin, I have an oil leak so could it be doing this because it's running a little low every now and then? I've alot of other people talk about the same problem but like I said mine has a new oil pump/pickup and new bearings.

 

No expert here, but my 400 had very low oil pressure when the cam bearings were bad.

 

Is your oil leak at the oil pressure sensor? Where is your sensor located - early 94's are above the oil filter, later 94's are on top of the block behind the rear edge of the intake manifold.

You indicate your synthetic oil is "thin".... are you using something other than the recommended 5W-30 (or 10W-30 is not exposed to 0*F ambients)?

 

yup cam bearings can do it too...

 

I'll have to check and see where it's at, I'm also going to take my manual oil pressure gauge to check and make sure it's not a false reading from a bad Oil pressure sensor.