oil pressure
 

Ok, I was sitting a light, and my oil pressure starting dropping, so I turned off on a road and when I started moving (revving the engine) the oil pressure went up to where it normally is (and never moves from). Anyways, anytime I let the car idle, the oil pressure goes down to just under half way (I know the factory gauges suck, I'm hopefully getting an Autometer one soon, just tryin to save for this winter's project, my 331. Any ideas why this is doing it? I've parked the car until I can get a straight answer, so the sooner I can find out some info about this the better!

Well, as rpms increase, so does oil pressure. The pressure goes down when the rpms go down, too. Maybe your crap factory gauge finally became accurate. LOL. How many miles? it's either the sending unit, or the bearing clearances. Both wear with age. as long as you always have 10 psi per 1000 rpms, you'll be fine. get a real gauge.

Take care,
~Chris

I'm getting a nice Autometer gauge soon. I think I'm getting the dash pod with a 5" tach, but it's weird because the factory gauge NEVER moved no matter what speed the engine was at. I knew it was working though because one time I put in some 10w-30 oil, and the oil pressure dropped very slightly. When I changed back to my regular summer oil, 10w-40, it went up. Anyways, the car has 76k miles on it, thanks for the reply.