oil pressure sensor location

[rockin1978TA]

My wifes 89 535i, shows the oil pressure message only when the car starts, then when you shut it off. Doesn't stay on when driving. Can someone give me the location of the sensor? I looked by the oil pan, and oil filter and can't see it. Maybe a picture would be good. According to the Bently book it's by the oil filter on a 525, or on the pan for an 535, I can't find it. It's been doing this since I bought the car in Oct, doesn't seem like I have low pressure.

[angusbn]

Item #10 on my 1989 535i (08/88)

[rockin1978TA]

Ok, let me look again tonight, so yours is on the top side of the filter housing? Maybe it's smaller than what I'm thinking, but I didn't see any wires around the filter.

[Ken35i]

I have an 09/89. Mine isn't on the oil canister, it's toward the back on the head...
RealOEM part 16 (http://www.realoem.com/bmw/showparts.do?model=HD22&mospid=47382&btnr=11_1906&hg=11&fg=15)
It's a bugger to get to...

[bubba966]

I have an 09/89. Mine isn't on the oil canister, it's toward the back on the head...
RealOEM part 16 (http://www.realoem.com/bmw/showparts.do?model=HD22&mospid=47382&btnr=11_1906&hg=11&fg=15)
It's a bugger to get to...

Makes me glad that it's in the pan in a 540...

[rockin1978TA]

Found it! Your right, at the back of the head underneath the coolant tank and wiring harness. Looks like I need to remove the tank to get easy access. Also, I notice the black casing is broken, and it only has 1 green wire. I'm assuming the message comes on when the car is started and shut off, because there is no oil in the head at the first 5 seconds the car is started then when shut off? It only comes on for about 5 seconds when I start the car, then about 20seconds when I shut it off. car built 11/88.

[Ken35i]

There is only 1 terminal/wire.
You shouldn't get the *dong* "Low oil pressure" alert. Just the oil light.
If you disconnect the oil pressure sensor, do you get the same behavour?

[Bill R.]

Found it! Your right, at the back of the head underneath the coolant tank and wiring harness. Looks like I need to remove the tank to get easy access. Also, I notice the black casing is broken, and it only has 1 green wire. I'm assuming the message comes on when the car is started and shut off, because there is no oil in the head at the first 5 seconds the car is started then when shut off? It only comes on for about 5 seconds when I start the car, then about 20seconds when I shut it off. car built 11/88.


Its just the same old same old problem thats been discussed a zillion times before.. the check valve in the oil filter canister is allowing the oil in the filter to drain down into the crankcase when you shut the engine off and it sits for a long period of time. On startup there isn't any oil pressure getting to the sender until the oil canister fills up and then goes to the rest of the system. When that check valve goes back you have to replace the canister since its a part of it. A few people on here have attempted to repair the check valve and Bruno and some others have made a bypass plate to allow external filters with built in check valves. On yours i would just check the Orings on the threaded bolt in the center of the canister lid to make sure they are good and then inspect the check valve in the bottom of the canister.... Its possible its your oil pressure switch but its pretty unlikely.

[Kalevera]

Makes me glad that it's in the pan in a 540...

It's actually mounted to the side of the filterhousing on 540s...The pan holds the level sensor, just as on the 535...