1984 E30. Old SOB! (car and owner)<G> the oil pressure light is staying on a fwew seconds longer than I am happy with when I fire the thing up. Where is the oil pressure sensor pick up point..and can I screw in a mechanical oil pressure gage to get a real PSI reading? Fitting thread?
It is on the passenger side of the engine forward of the motor mount bracket below the oil filter. I can't remember the thread pitch, though. I think it is either M10x1.25 or 10x1.5. Not too helpful, sorry. BTW, oil will come out if you unscrew it, and continue to come out, so if you go this route, do it during an oil change and take it with you to the parts store.
Ah! Lovely suggestion.<G> and the oil change is due soon (I don;t have a Bentley here at home) what is the acceptable oil P range at idle and 2000 rpm for an M20? do you recall? (if not, i suppose I can find it in the big book).
I wonder if your car has the same 1.8l engine my '81 320i did - maybe different fuel injection, I _think_ the 320i had.... k-jetronic? Anyway - IF they are similar, my 320i started to have the oil-pressure light stay on, and intermittently pop-on @ around 150k miles. Oil pump was weak and should have been replaced. Sounds like getting an oil-pressure reading is a good plan.
Ah - 84 E30 made me think 318i. I imagine 325e's could have build dates in '84; as I recall BMW NA introduced the 325e as an '85 model.
Buy a switch. FWIW, I don't bother with anything else before replacing the oil pressure warning light switch. The things are only about $7. You can hardly buy a proper adapter for an oil pressure gauge for that. I doubt you can rent a gauge, if you don't already have one, for that amount. Those things are so failure prone, I am perfectly comfortable saying that, if it hasn't failed yet, it will. If that isn't it, you're only out $7 and you still have a good spare. On the positive side, you haven't pulled and rebuilt your oil pump for no good reason.
I plan to grab a sensor at the junkyard and then see what can adapt that to my external oil pressure tester. I'd like to know real numbers anyway, and if the #s are good, the switch is the most likely culprit for the flickering light. I suspect the lump was rebuilt at some time...compression is as new (150 psi across the board)...???