no oil pressure at hot idle
 

So i've been chasing a no oil pressure issue (at least on my cluster) on my 95 lt1. This happened out of the blue one day as i stopped at a light. Since then, i've replaced the sending unit sensor, and today I changed the oil filter, and put in 10w40, hoping the thicker oil would make a difference. I also just happened to notice that if I bring the car up to 2k my speedo climbs up between 5-10mph kind going back and forth. Idk if maybe the cluster is going bad, and I have no issue at all with my oil pressure?

Also if I bring the car up to 2k i'm reading about 20psi. Another note, the engine doesnt tap or knock at all when cluster reads 0psi.

First thing to do would be to verify oil pressure using a mechanical gauge. You need to figure out if it is an electrical or mechanical problem. Once you verify if the oil pressure is actually zero or not, post the results and it will make it easier to diagnose.

Agreed. Use a mechanical gauge. Something might have broke in the cluster. Is the motor knocking at all?

How many miles? LT1 are notorious for low oil pressure. 10-12 PSI at idle is actually common, lower then that and over 100K miles you are probably looking at a new new oil pump or replacing the pump spring.

motor doesn't knock at all. Car has 141k. I just replaced all the gaskets on the engine. New timing chain set, new distributor. Pressure was fine for the first 500 miles after I replaced everything.

As stated in a previous post, first thing is to run a mechanical gauge and see what psi it reads then go from there

Believe it or not ALLDATA says that that normal LT1 oil PSI at hot idle is 7-10 PSI. that was odd for me coming from the school of SBC's need at leat 30-40 PSI. I would do as stated above

SBC do not need 30-40 psi at idle. the old rule of thumb was basically 10psi per 1000 rpm.

Have you put a mechanical gauge on it yet?

My 95 LT1 use to idle @ 5psi and @ WOT was around 40psi.. It had 73,000 miles on it..

i have the same issue... after much reading ive concluded its just an LT1 thing. 145k miles on my LT1 and at hot idle it drops down to just about nothing on the gauge, but if u tap the gas it jumps back up

also i replaced the presure sensor when i did the manifold gaskets and thats when i first noticed it being low, so it could be a ****** sensor i bought

Probably due to wear on the bearings and a tired oil pump. A high pressure spring will definitely help.

haven't had time to get a gauge on there yet. work's been crazy busy lately and by the time i get home i don't want to move, lol. keep you guys updated though.

so i finally got a gauge on the car. At hot idle i'm reading 2-4 psi. and at 2k rpm, i'm reading between 22-24.

Yeah, that's not good. I'm sure a rod/main bearing is on its way out already.

So where do I go from here? Lol

Rebuild the bottom end now or later. At least do a gm white spring in the oil pump.

To fix it right, freshen up the rotating assembly. Might be able to band aid it with a new oil pump to get a little more time out of it, but if the oil pressure is that low now, the damage is already done.

acceptable range hot idle as stated from gm is 6-12 psi at the lowest. i read that somewhere i think on a vette forum.

that sucks though, good luck man

Considering the oil pressure was a problem only after you changed your gaskets (which ones did you change and why?) it would lead me to believe that perhaps you contaminated the engine/oil pan/etc.

I would put in the pump / spring. I've done this on a few cars and it does bring the oil pressure up to where it needs to be.

Here is an old thread that gives the part numbers.

http://www.njfboa.org/forums/showthr...eferrerid=1095