oil pressure sensor or switch - BMW Forum

DonJ · 01-02-2011, 01:14 PM

Happy New Year!

1991 535i (M30) - This has only happened once, but earlier today I as I shut off my engine, the dash display said "oil pressure sensor" "see owners manual".

It has been cold (14 F last night and 24 F now). The car had not been driven for 2 days (battery having problems in cold weather and had to jump start).

After I got the car started and let it idle for a while I took it for a drive and it ran fine. The oil pressure sensor message came on as I shut it off. Later on, I took the car for another drive and did not get the message again.

So anticipating a problem, I have searched on an oil pressure sensor and have not been able to find one. I have found an oil level switch, is this the same thing but different terminology?

Thanks!

gidgaf · 01-03-2011, 09:53 PM

*It's quite probable that at idle your engine is at it's lowest oil pressure, then when you turn it off the oil pressure drops to zero. During that time your computer detects the lowering oil pressure, and lets you know. My oil light does a little flicker at a 600 rpm idle only when fully warm, and while it does worry me a bit the Bentley tells me it's normal. I don't think you have anything to worry about if this is the only time it does that.

DonJ · 01-04-2011, 08:14 PM

Thanks gidgaf for the reassuring comments - it hasn't done it again. I think it was a cobo of it sitting for a few days in cold weather, battery problem and all that. Turns out my battery was low on water, so I filled it, charged it and all is well (except we still have the cold air - brrrr).

DonJ · 01-04-2011, 09:33 PM

but the question I'm still trying to find an answer for is this . . .
the display said "oil pressure sensor" and the owners manual says for the sensor to see a mechanic. I searched on oil pressure sensor and came up empty handed. But there is an oil pressure switch (I screwed up my O.P by saying level). So is an oil pressure sensor and switch the same thing?

gidgaf · 01-07-2011, 05:04 PM

> So is an oil pressure sensor and switch the same thing?
Mostly. Make sure you and your mechanic are using the same words for the same objects at the same time . Oil pressure switch/ sensor, or oil level? If the only time you have too low oil pressure is when the engine is off, I think you're good to go.

DonJ · 01-08-2011, 02:06 PM

I found out from an on-line parts place that the oil pressure sensor and oil pressure switch are the same thing. It hasn't appeared anymore so I think I'm OK.

I screwed up my original post when I mentioned level - my mind knew what I wanted to say but my hands typed something different.