smcnealy

So my oil pressure gauge seems pretty high. It idles warm around 40, starts cold at about 60, and before the car is totally warm can get near 80 while driving.

I thought I had some old or too thick oil in there, last change was ~4k mi and I didn't do it myself. So as of yesterday, I've got some new 5w30 (valvoline dino oil) in there, and the same thing is going on.

Is there something mechanically wrong that can cause this?
Do I just need to check the oil pressure sender and the wiring? Or maybe just the gauge could be off?

I have no complaints about how the car is running.

smcnealy

Oh yeah, the car's a 2000 z28 with about 114k miles on it.

And might be unrelated: I did have to replace a pretty bad looking PCV hose. So I think it's getting some (but not a lot of) blow-by for a while now.

And one more thing I remember seeing: it does seem to bounce around a bit more than I'd expect. Kind of a low frequency (2Hz?) vibration. Not all the time, but sometimes.

wht01ws6ta

iTrader: (45)

Dumb question but does it read 0 with the engine off and the key on?

smcnealy

Yeah, it does. Thanks for the brainstorming, though.

9000th01ss

iTrader: (10)

Your car have a manual trans?
I ask because I can only get near 80 with higher rpm than the automatic will allow during normal driving.

I just installed an autometer oil pressure gauge.

The factory gauge reads higher at low rpm, and lower at high rpm.

My point I guess is all gauges read different, especially factory gauges.

PCV will not have any effect on oil pressure.

smcnealy

It's an auto. Has the factory gauge. And it doesn't really need a lot of RPMs to read high.

I'm thinking more and more that the pressure can't really be that high and that it's a bad pressure sender. Apparently it's behind the intake manifold? Maybe I bumped it and messed it up since you can't see what you're doing back there. Looks like a pain to replace...

I guess I'll be looking into the sensor as a problem. I was really hoping people would say, "oh, everything's fine."

RacerXLs1

iTrader: (14)

That sounds about rite...

wht01ws6ta

iTrader: (45)

Mine always reads high but it reads almost 20 with the engine off and key on so I just subtract 20 from the pressure it says and I still have good pressure so I'm not too worried about it. I broke my sending unit when changing the intake and when I replaced the broken sensor with a new one it started reading high then.

Psychopjv

iTrader: (16)

mine read 65 on cold start 40-45 hot idle and pre-warm up driving was around 80-85. nothing to worry about. i melted three pistons due to a nitrous issue and my bearings/crank/rods all look to be in very good condition. 99 30th M6 110k.

DCsLS1

i thinks its fine mine is about the same 60 on cold starts 40 on warm idle, and up around 60-80 driving around

SonicBoom

iTrader: (1)

Yup, mine does the same when it's cold out.

406malibu

yup when its cold mines the same, nothing to worry about.

01ssreda4

iTrader: (96)

about the same pressures here too.

twitchtwice

iTrader: (12)

it never really gets cold here but warm idle is 40 and cold start is like 50

00_STANG_KILLER

wow 114k and the pressure is still that good you should be happy! my 40k ss runs that kinda pressure so your good to go....BTW id use synthetic 5w-30. Thats just me though.

elias_799

iTrader: (8)

yea, don't worry man, everything is working properly. i have the exact same pressure in my 02 z28

jblack245

I use GC 0w30 and I have a lil over 150k miles and my oil pressure is like that too

silverM6TA

iTrader: (5)

my pressure is the same except for after warm up. it just below 40, i would say 38ish. 65,xxx. so your good and have nuthin to worry about.

nick123

factory gauges arent very accurate i wouldnt worry about it at all

4WOFURY

iTrader: (2)

Sounds right. How is the pressure when it's warm? 80 psi driving around cold sounds about right.