ANOTHER oil pressure question.
 

Car is a 99 formula, has 123k, A4 yadda yadda yadda......

Lately for the past 10k miles or so, the oil pressure has seemed a little low, like 20-25 psi hot idle, 30-38/40 cruising and only goes up to about 50/55 wot. It has the stock oil pump and usually sees 5w30 oil. Is it possible that I'm seeing low pressure from bearing clearances opening up a little with the mileage, or is it an oil pump going bad? I know it isn't bearings, other than typical ls1 noise, it's whisper quiet. No chunks of bearing or metal specks in the oil when it's changed either. Still runs like a champ, just the oil pressure issue, also when I let off the gas, the pressure actually climbs about 5psi, then drops back down about 5 when i step on the gas again. I'm really stumped on this, so ANY help would be awesome.

First thing I'd do with weird readings like that is hook up a mechanical gauge or replace the sending unit.

I am having the same problem except my car has 70k miles on it. I will be holding it a 3500 cruising down the road like im about to gun it and the oil press will be 45 or so and then I gun it and it drops to around 40 and then when I let off it goes up to about 45 and slowly comes down as the motor winds down. At idle i have like 20 or so psi. I know that you only need 3psi per 1000 rpms but it seems like almost all other ls1 cars run higher than this.

I dont mean to jack your thread but I want to know too. I feel like we are having the same problem.

Check with mechanical. I have replaced mine (3) times, and I had different readings, if any at all, every time.

Switching to 10W-30 oil will increase your oil pressure over 5W-30.

Russ Kemp

Weird.... yours is the 5th 99 model year f body I've heard of doing that EXACT stuff *including mine*. Maybe it's an inherent problem with that year?

40 at normal driving id right where you want it