I installed a trw high volume oil pump in my 76 chevy 350. I have a digital oil pressure gauge. when i initially start up the car it has about 75-76 lbs. of oil pressure. When i start driving down the road after about 5 minutes my oil pressure just slams to about 25-30 lbs. I'm goin about 45 on a turbo 350 trans. I don't know how many rpms i'm turning. but anyways my pressurew drops alot. cruising at a constant speed my pressure can vary from 25-45 pounds. i think that is too much variance. by the time idrive for 15-20 more minutes my psi will read from 0 th 13 psi at idle in drive. entirly too low. i have to put it in nuetral or park to get the oil presure up to 20psi so feel a little more comfortable. why is it doing this and how do i fix it?i have a 7 quart oil pan so i don't think having enough oil is the problem.could it be the gauge? should i put a mechanical gauge on it to see if it reads the same? Also i notice the other day when i got home form school(about 25-30 min) a slight amount of oil was leaking around my intake bolts on my edelbrock performer intake. did it warp? should i let it heat up a little and torque the intake down a little more or will that just cause more problems?
I would see f you can have a garage test the preasure with a mechanical gauge.They just look like a compression tester and you check it under the hood. When oil gets hot it usually drops preasure.I have had my share of low preasure engines. If the engine has a lot of miles on it and you test low preasure it is a sighn of worn main/rod and possibly cam bearings .Another thing to check is your coolant temp .If the coolant gets too hot it can do the same think. Dont tear into your engine because a faulty gauge says so.So if the coolant temp is ok and it turns out your oil psi gauge and sending unit are accurate. Try some 20w50 oil this will hold more hot preasure.If you live where it gets cold out this oil may be hard to turn the engine over ob cold start,
i will check my oil pressure with a mechanical gauge. i really don't think the engine it wore out. i bought it used but when i had it taken out and put that oil pan on it had no oil build-up on the pistons or bearings so i think it was just freshlyrebuilt before i bought it. granted it had been sitting for a year or so but it was still very clean inside. do you have any ideas about my intake leaking oil around the bolts? its not alot at all. i can just see little oil spots around it. but another thing about the oil pressure it is could idle for 30 minutes and never lose any pressure. it would still read 75 pounds or so. it is just when i drive down the road and after about 3-4 min my gauge will crash from 75 lbs. to 30. does it sound like my gauge or sending unit could be messed up?
Shoot what was the question? Oh try removing the bolts and put some RTV or permetex #2 on them after you cleaned all the oil off em.This bolt thing is as common as gas in a carb.30 lbs hot preasure is good. You may have a preasure relife spring issue with the oil pump. BUT CHECK IT WITH A GAUGE.There could be a issue with your charging system effecting your in dash gauge.