'92 RS oil pressure guage reads normal when the engine is cold (60-70psi). After a few minutes of driving the guage drops to the red zone. every once in a while while driving it will spike up to 50 psi so I know I don't have an oil pressure problem it just pisses me off to see low pressure on the guage. I did replace the sending unit (above the oil filter) and no change!! What to do next is my ?. Is it the cluster maybe?

 

It could be the engine itself. At idle and warm, the stock engines only have around 15 PSI or so. If there is a lot of internal wear, it will be even lower. Try hooking up a mechanical gauge and see what that says. If you really want some oil pressure, install a high pressure, high volume pump. Cold, mine reads way, way past 80 PSI with the HP pump gm put in my crate. It pegs the needle in the winter with 10W-30. Im waiting for my oil filter to explode one of these days. Probably going to go to 5W-30 in the winter.

 

I know that it might sound extreme but Mobil One 5w20 is what I have been running in my GM 350 TBI crate engine. It is a fresh engine that gets beat on pretty hard and doesn't seem to mind. It has 60-70 psi of oil pressure at normal driving speeds and 35-40 psi at idle when hot. Thanks GM for the High Volume High Pressure M55-HV oil pump that GMs Goodwrench division puts in their crate engines.

 

does then lo3 oil pressure sender work off a 5v signal?

 

No, it is a variable resistor that grounds the gauge through it. If the circuit is open it will peg the gauge to the MAX reading, IIRC.

 

Thanks guys but I really don't think its a pressure problem. Its not that the pressure goes down when the engine is hot. The guage stops working and stays at like 10 psi at idle or at 5k. It spikes up to 40-50psi for brief intervals while driving, sometimes.

 

well ****, i just need a oil and or fuel pressure sender that works off a 5vsignal