My oil pressure gauge is acting like a tach. As the rpm'* go up the oil pressure gauge rises to the max. Any ideas what would cause this?

maybe the pressure relief valve is broke, or maybe the sending unit is bad...

I'm going with a bad sending unit....Pontiac'* are notorious for bad senders.......And mine is acting the same way....but doesn't matter RPM'* at all.....It'* just all over the place.

Hmmm. Is your engine new or rebuilt? How many miles on it? If it is a bad relief valve, you will be putting a lot of pressure on seals and parts that aren't made to withstand it. If something pops, you could lose all your oil in a really short time. You need to make sure what'* going on here so you don't suffer some really expensive damage when a cheap fix could have made things right. Checking, replacing the relief valve, I don't think, is a very difficult job.

Its not, probably 15min. IIRC you don't even have to pull the oil filter. Here'* how I did it, I might have forgot a step though:

1. Raise car
2. Remove passenger side tire
3. Remove splash guard
4. Remove oil pressure sending unit
5. Remove 4 (IIRC) bolts holding the oil filter housing to block
6. Carefully pull housing away from block. A metal plunger and spring will come out.
7. Tada

Prolly need to throw a "Disconnect oil cooler lines" in there too.

The symptoms go exactly with what a stuck relief valve would indicate, although the probability definately leans to the sensor.

Thanks everyone for your help. I will replace the sending unit first and go from there.

I will keep you all posted.

Thanks again!