Over the last month or so, the check gauges light on my '94 LT1 M6 illuminates infrequently. I've already done a search and didn't find anything that covered exactly what I was looking for.

I read through the FSM and didn't find much mention other than the light will illuminate when the oil pressure, oil temperature, water temperature, or voltage hit the red range.

In my case, I think it's related to the oil pressure. When the car is cold, the oil pressure is fine, no light. When the car is warmed up and moving at speed, no light. The only instance the light comes on is when the car is at operating temperature and idling. Even then, it isn't solid. It will flicker as if it's right on the edge of the red range. When I look at the oil pressure gauge when this is happening, the gauge is *not* always in the hashed range. Does anybody know at what point the check gauges light is triggered in relation to the oil pressure? I was not able to locate that information in the FSM either. Also, I'm running 10W-40 Mobil 1.

How can I go about determining if the problem is actually low oil pressure, or if the sending unit is toast?

The car has 170k on it and runs great. No odd noises from the bottom end or the engine in general. It is a daily driver obviously. I don't beat up on it, but I do drive it like it's meant to be driven.

 

Check OP with a known working mechanical gauge

Hot engine at idle , hi miles ; might be bleeding off some oil pressure through the bearings

 

I need to find a mechanical gauge. I don't have one. Where would it be connected I wonder? Same location on the back of the block where the sending unit is?

As for bleeding off pressure through the bearings, that was my first thought. Just not the one I wanted to entertain as being the case.

 

It can run for another 100K loose, older engines ran that way with no problems.
Don't sweat it