Camaro73

I have a 98 Trans am with 140k. The oil pressure at idle is at the line right before the red Mark but when I'm driving it goes up to 40 or more. Is that normal?

delrio_bird

Im pretty sure a Bird rolls the same way but it sure doesn't sound normal. My car for instance, 95 Bird with 160k and an oil leak at the sensor......

From a cold start: 80
Few miles of driving (~10 miles): 45
Longer drives: 35

All at a redlight/standstill....mind you I have a leak. So I expect it to get better after that's fixed. I'd get yours checked out

Camaro73

Ya mine has no,leaks. But at a light it'll go down but driving it goes up.

Camaro73

Car also isn't low on oil

Wheelman916

My '95 Z reads a little low as well. Though I've heard many LT1s runs low psi regularly.

All readings taken from the in-dash gauge.

Cold idle: around 40
Cold driving: >50 (50 to 55)
Hot idle: 20-21
Hot driving: <40 (38 maybe)

When the RPM drops off idle to let the clutch out, it dips closer to the red, but as soon as the RPM climbs, pressure approaches 40. Dipstick shows a full oil pan.

I want to hook up a mechanical pressure gauge and see if the in-dash is accurate or not. I'd be happier with about 10 extra psi across the board.

Camaro73

That's almost exactly how mine is but at cold idle it's over 40 but warm idle is less than 40 at the Mark before red?

delrio_bird

My next 2 theories then is a bad sensor or oil pump

Camaro73

I hope not cause I don't have the money to fix it lol

delrio_bird

Sensor is easy fix.

Camaro73

I wouldn't know where it's at, I've done a lot if research on these engines because of a swap I plan on doing in my Camaro but as far as experience with these engines I have 0

Jr.Samples

Put some thicker oil in there like 10W40. As an engine wears there becomes more tolerance in the bearings where it builds from.

As oil warms it gets thinner causing lower pressure.

Good luck

dailydriver

IF you have 'baby hands'!! (It's behind the intake manifold, UNDER the cowl, with LOTS of plumbing/tubing/wiring harnesses in the way (if they were not all removed, like many on here do).

Camaro73

What about trying diesel oil for 1k miles or so to clean everything good?

chrysler kid

iTrader: (14)

The car is fine. As long as oil psi increases steadily during acceleration everything is good.

My 98 trans am had 20 psi warm idle but rose to 45 psi with rpms. As long as the pump is building pressure its ok to drive

1_MEANZ28

iTrader: (4)

like mentioned above..use thicker oil 10w40 should be good try if that does anything ,and replace oil pressure sending unit.if the issue is still there you will need to replace oil pump..been there done that

dailydriver

Is my engine the exception on here, as my hot idle pressure NEVER drops below 40 psi (at least according to the factory cluster gauge), and the ~2000 rpm, HOT, cruise/steady state pressure is never below ~55 psi, and WOT HOT pressure is never below ~60-65 psi???

Also, these pressure readings are ALL higher in the cold winter months.

_JB_

iTrader: (33)

Mine runs very similar (never below 40psi idle and 58-60psi cruising) on 10w30 oil. Its been that way since I got it back in 05.

Camaro73

So maybe it's the sensor?

chrysler kid

iTrader: (14)

1998 was the only year with an accurate analog gauge. 99+ is just a dummy meter. On the new camaro I believe oil pressure is 30psi at idle

Cole Train

iTrader: (30)

Mine when it's really warm it idles around 35 psi but it it fluctuates about 5 psi everytime my cam chops lol when i'm cruising it's around 55-60 psi.