Oil Pressure light at idle (YAY!)

[Beach Bum]

Oil pressure light is coming on blah blah blah.

Does anyone know what the threshold on the switch is?

Standard oil pressure issue. It was coming on at idle before the last oil change, but afterward (until now, ~1200 miles later) it's coming on again. with 172k on the motor and plenty of AutoX it's probably time to replace the rod/main bearings. Or it could be a clogged pickup. Or a bad sensor. Who knows. I'll probably pick up an adapter plate and get a proper gauge, then pull the pan (dammit) and check the pickup. The pump could be bad too...

Ugh, so many ways this could be wrong and NONE of them cheap.

Am I missing anything here?

[MR 325]

Curious, what oil do you run? These care run pretty low pressure at idle, 5-10psi. I think the light is at 2psi but don't quote me on that. An oil pressure light is a sign of a bad oil pump most likely, bad bearings won't cause the light to come on.

[azael325i]

I have the same problem :(

[jlevie]

The light comes on when the oil pressure drops below 7psi. The wrong oil, a clogged or wrong filter, a bad pressure switch, or wear in the engine are the causes of the light coming on at idle.

For the climate this car sees, you should be using 20w50 dyno oil all year. I use Brad Penn racing oil, but Valvoline VR1 is almost as good. The best filter I know of is the Mobil-1 filter and the second best is the OE filter.

Replace the oil pressure switch with a new part, change the oil and filter and see if that helps. If the light continues to come on or flicker at idle, temporarily replace the switch with a gauge and see what the oil pressure actually is. If very close to 7psi, you might be able to postpone an engine rebuild or change by switching to a 60 weight oil.

[nomansland92]

bad bearings won't cause the light to come on.

^???? bad bearings will cause low oil pressure, which can make the warning light come on.


anyway i'd get a oil pressure tester and see what the true pressure it is.

[Beach Bum]

Wonderful words of wisdom

Thank you for that, few things I missed and you seem to have covered all of it. I'm using Catrol GTX 20w-50, I wanted to change it right then and see if I could get the light to go back out, but no dice, of course. I'm using a Purolator Gold filter, PL24466. Couldn't source a Bosch or Mobil 1 at the time, I usually get the Bosch.

Follow-up question:

Anyone got any leads on a sender that will mount in the stock oil pressure switch port? Or, hell, fabricate a tee that I can use for both the idiot light and a gauge?

[jlevie]

I don't know of sender that will mount where the pressure switch goes, but you can get an adapter that allows the user of standard NPT threads. You can go from the adapter to an NPT tee to mount a sender and pressure switch.

[Beach Bum]

I don't know of sender that will mount where the pressure switch goes, but you can get an adapter that allows the user of standard NPT threads. You can go from the adapter to an NPT tee to mount a sender and pressure switch.

I'd been searching about on the web and here while waiting on a reply and I saw the adapter, thanks for the tip and all your help.

[Jaxx_]

parker performance had a kit that my PO purchased. You can get the adapter/sender/gauge as a kit.

[seatown88]

I used a M12x1.5 to -4an adapter in the location of the oil pressure switch then ran my line to the remote mounted oil pressure sender mounted on the fender well. Simple, fairly cheap, and I don't have to worry about vibrations wreaking havoc on the sending unit/adapter block