I just installed a new front cover with oil pump. primed with a drill and cold motor has good pressure. At cold start up It shows 80 psi then after it gets up to 190* it drops to 10 psi at idle. Oil pressure does rise with rpm's but will fall back to 10 psi at idle. No lifter noise or knocking. Any thoughts? New cover is a Proform from Finishline Motorsports it was there loaded cover. Could it be related to the pressure relief valve?
No, the relief valve simply limits the maximum pressure the pump will produce. At idle, the pump would not be producing enough volume to open the relief valve. Hot oil pressure depends on two main factors, internal oil pump clearances, and main, rod, and cam bearing clearances. While 10 psi at idle is a bit low, as long as you have 11-12 psi /1000 RPM at higher RPM, you will be fine. http://www.v8buick.com/index.php?threads/oil-pump-clearances-and-oil-pressure.326597/
It's not a new build built in 1999 just not many miles around 2,000 or less. Its been since 2005 since I drove the car and it never had an oil pressure gauge until I just installed one. It was my fathers car for the last 20 years and now its mine
Brandon, what oil are you running? being in Fl. a thicker oil would be ok, I'd run a 40wt. syn. Also,10 psi at idle doesn't really bother me when hot. As Dennis Manner used to say, if its over "0" at idle your good to go. gary
I'd expand that to "four" main factors; the two you list along with IDLE SPEED and oil weight (viscosity). 10 psi hot idle oil pressure is nothing to be concerned with...if the idle speed is low enough, and the oil is thin enough.
As long as it reacts when you hit the gas. My 71 is like that. It sits under 20 at idle. Its over 60 when it counts though. Incredibly, the beater is 35 psi at 800 rpn.
It may have had that oil pressure all along being you just installed an oil pressure gauge. As other have said, idle rpm affects idle pressure, so does oil weight. More importantly, what does it max out at hot? At what rpm? Another important factor is the gear end clearance in the oil pump. You said it was a loaded cover, but..............
Mine sits at 5-7psi at hot idle. Scared me to death for the longest time. Then Denny Manner himself sat in my car and watched the pressure gauge when I spoke with him about it. Without hesitation he said "it's fine, drive it".
