wishful

Would anyone know why an oil pressure gauge would read at mid-range with the car not running? I am considering replacing the oil pressure/sending unit however I am wondering if it may be the gauge itself. It climbs to high after the car is started and running, indicating that it is functional, however it only returns to mid-range after I turn the car off.

BangScreech4-4-2

Is it a gauge from a factory Rallye Pac, or is it aftermarket? Mechanical or electric?

wishful

It is factory Rallye pac and electric I am assuming, I did remove the connector (with the car off) from the oil pressure switch and the needle remained in the same position.

Octania

I don't think the needle position when not in use has any relevance. Some go to zero, others don't. As long as it behaves when energized, it's not to worry about.

wishful

Thanks Octania, I had considered that, yet wasn't sure. I only assumed it would/should go to zero. Nevertheless I now know that my oil pressure is higher than normal based on the gauge reading...although I also questioned whether stored energy within the oil pressure /sending unit would normally set the gauge to zero, when it isn't energized.....

oldcutlass

Do you mean engine off but the key on or key off?

wishful

Engine and key off

oldcutlass

What happens with the key on and engine off?

wishful

With engine and key off it sits right at mid-range with key on with engine off it pegs upward towards low a bit about 3/4 of the way to the next mark on the gauge

oldcutlass

The gauge has no real neutral position in the key off position, it just stops. With the key on and engine off it should read 0 off the sender. With the key on and the engine on it should read what the oil pressure sender is calibrated to. Since these gauges are not very accurate, if it reads anything warmed in idle its a good thing. If you want an accurate measurement I suggest an aftermarket mechanical gauge.

wishful

That's exactly what I'll do Thankz Eric

wishful

Thanks to all, I have yet to get a mechanical gauge to get an accurate measurement, however I did replace the pressure switch itself to see if it made a difference.... and yes it did. The gauge now reads at 0 with the key on and engine off (as stated above), it pegs slightly downward with key and engine off past zero and reads slightly pass mid-range while running.


Thanks again everyone for your input. Issue resolved