I don't know if this is a sticky or not but i wanted to make my own for my own questions. at start up my oil pressure is a little above 40psi. after driving around at normal speeds its around 35psi. if i get on it. it will go back up. also at idle my oil gauge goes crazy and bounces back and forth like crazy from 10 to 20psi. only at idle. then when i drive its back at 35psi. im useing pennzoil HM 5w-30. the car has 143k on it.

 

be a good idea to hook a mechanical gage to it to get an idea of whats really goin on. could be the gage, the sensor or something more serious like a bearing beginning to fail.

 

great.....

 

i forgot to add it does the 35psi on a hot day. the last few days its been 80something here and thats when it goes to 35psi. on a normal night it seems to be a hair below 40. i live in pa where i dont stop alot theres not alot of lights. however when im in DE i been stopping alot at lights on them hot days. so when i idle it does it bouncing thing then when i drive it goes to 35..

 

We talking factory gages? I would guess 98% of the time when a customer shows up with a oil pressure issue, if there is no noises or nothing like over heating has just happen its a gage/sending unit issue.

I am not a ls expert but a general rule is 10 PSI per 1000 RPMs. Much less then that and you can damage the motor.

 

when i change the oil i put 5qts in. i know it says 5.5 but its always full when i check. so. idkk

 

Even if it is low that would have no effect on oil pressure. You could be 2 qrts low and it would have no effect on oil pressure at idle. When your low on oil higher RPMs can be effected because the oil does not run thru the motor fast enough and the oil pan runs out of oil.

 

My stock LS1 had 103K on her and would run about 30-35 psi at idle when hot and would jump up to about 60-70 at WOT. This was on a mild cam turbo car. And for once i am going to say Gorn might be a little off. At 2 qrts you may notice a change in oil pressure because of higher oil temps. However it would be a small change and i think your sending unit might be the issue.