A while back I changed my gauge needles to camaro needles. I know my fuel and voltage gauges are correct. I also know that my engine temp is incorrect and I plan on adjusting it. However I am not sure about my oil pressure. It seems to read low.

Here is how it sits with the engine off and the key in the ACC position. Seems like it should be closer to the orange hash mark.

When the engine is warmed up it is around 20 PSI at idle (approx. 600 RPM).

 

20 psi at idle ok. 40 or so when driving and I believe around 50-60 at cold start up

 

If the engine is off, it should line up more closely with the orange hash mark.

As newguy stated, the observed pressures sound good.

I have used my Autoenginuity scantool in the past to help friends do overlays and/or change needles as it has the ability to command gauge positions for exact alignment.

 

I was thinking of picking up a cheap mechanical gauge and hooking that up to see what that shows.

 

I had the same issue with an aftermarket (Equus) brand. It was damaged and had a new one sent. I would think the orange mark is your starter point as well.

 

I cant get a mechanical Bosch gauge from my local advance for about $20. I may just go that route. About 2 years ago I had to replace the engine because I lost pressure. It started like this. It progressively got lower and lower. Now when I last changed my oil it didn't have metal flakes in it so I am hoping that it is just the gauge.

 

My oil pressure gauge is pinned all the way to the max psi and doesn't move when i start the truck i believe its just a bad cable. bad news is i can't find it on LMC.com can anyone help me find the cable that runs from the engine through the firewall to my computer? i got an 88 k5

 

Just find the oil pressure sending unit on the engine and follow the wire from it. Open circuit here will cause gauge to go past max and stay there.

 

I have seen a bad sensor cause the needle to go all the way up. In my 92 K1500 it just bounced up and down from 0 - 60 and back. The sensor is under the distributor and the distributor has to come out to replace it in an S-10 or blazer with the 4.3. I am not sure where it would be on an 88 K5.