Jayson95GT

So I start my car up yesterday and notice that the oil pressure is reading lower than normal. Its in between the a and the m instead of the a and the L like it had been since I rebuilt the motor. I found that once I drove the car for several miles it went back to its normal reading between the A and the L. It didn't make any sense to me how a motor that was hot could be reading more pressure than when cold... usually goes the other way around. So I did some research and have found some information that shocked me. I was told by a reputable source that the oil pressure guages on fords are fake! The "sending unit" is nothing more than an on/off switch and that there is a resistor in the I/C that makes the needle read good as long as there is some kind of pressure turning the switch on. Is this true?

pete88gt

all the crap you've got done to your stang, i'm surprised you don't have an aftermarket gauge anyway.

the stock gauge does work, and does fluctuate with pressure readings. you may have a bad oil pressure sending unit or your gauge may being taking a crap.

Jayson95GT

Ya, im planning on putting an aftermarket one in soon, I would like something a little more accurate than "normal" lol. So how does the stock system work? Does with pressure switch on the timing cover vary in resistance or something depending on the amount of oil pressure?