Check light oil light purpose?

[steerfromtherear]

The oil light on my roof check lights is coming on. I presume this is an oil level warning light as opposed to oil pressure as that is covered by the dash oil light yes?

If it is indeed a oil level light any ideas on why it has come on when I am halfway between full and empty on the dipstick?

The only explanation I have for it is a dodgy sensor as my check lights also say I am out of washer fluid when its full.

Thought it would be best to check on here as I dont like to take risks with oil related issues.

[Ziggy]

Yup; oil level. Mine comes on before you get to empty too - nice to get a warning I reckon!

[JimmyC]

On you washers, is the sender float in upside down? sounds daft but have a look ;)

[handpaper]

It's supposed to come on at that point, and scare you into topping up the oil before it's too late.
For your washer fluid, check the float sensor is the right way up - it can rotate and read reversed!

[pnd]

try topping the oil up then it should go out if not its the sensor in the sumpwhich needs unsticking/replacing.

[steerfromtherear]

Brilliant thanks guys, all my other BM's have come on at around the minimum mark so I thought it was playing up. I'll stick half a litre in and see how it goes.

[Brianmoooore]

. I'll stick half a litre in and see how it goes.

Don't expect immediate results - the sensor can take half an hour to respond.

[nickfromgills]

Does anyone know where the oil level sensor is located, or how to replace it? It's a really annoying gremlin affecting my '87 325i just as you guys above.
Funny thing is, it always comes on after I park the car with two wheels up on the pavement outside my girlfriend's. The only way I can get rid of it is by driving for a couple of miles and then switching off for a few minutes. Passengers think it's something major about to blow and I'm sick of explaining, ha! I guess I could always kill the bulb...

[liam012]

sounds like a sticky sensor, when you park up on the kerb the oil in the sump where the switch is falls away and leaves the sensor thinking you havent enough oil.
very easy to change for another one - you will see quite a heavy gauge wire come from the block (just behind the timing wheel) down on to the sump about 2.5 iches long the sensor it is connected to is the one you want 2 bolts hold the sensor in to the top of the sump.
its the only sensor on the aluminium sump so going by that you cant go to far wrong.

[stonesie]

Just clean the area around it first, general crap likes to build up around the sensor and its best not to let it fall into the sump

[Turbo-Brown]

That light saved my engine on the way back from it's RR session.

I really wouldn't disable the builb as you never know when an oil leak migh t spring up and cause some kind of engine threatening situation.

[Brianmoooore]

Does anyone know where the oil level sensor is located, or how to replace it? It's a really annoying gremlin affecting my '87 325i just as you guys above.
Funny thing is, it always comes on after I park the car with two wheels up on the pavement outside my girlfriend's. The only way I can get rid of it is by driving for a couple of miles and then switching off for a few minutes. Passengers think it's something major about to blow and I'm sick of explaining, ha! I guess I could always kill the bulb...

I don't think there's anything wrong with this sensor at all! It's just doing its job!
Because of the way you are parking, the sensor sees a low oil level and reports accordingly.
Once the sensor has turned the light on it won't go off until, a) the car has been level long enough for oil to flow into the sensor through the very small hole in its casing, and, b) the ignition has been turned off and back on again.
The problem might be solved by keeping your oil level right to the top of the dipstick and might be helped by taking out the sensor and soaking the whole thing in a baked bean can of petrol, flushing it several times, as I've described in earlier posts.

[Morat]

What is quite scary is how low the oil can get without the pressure light coming on. I've been to the bottom of the dipstick before and the oil pressure light (which hasn't blown, it tests fine with the ignition) didn't come on. By the time the oil pressure is low enough to put the light on I think you'll be wishing you still had the level indicator active.

[handpaper]

Morat - that's because oil level and pressure aren't directly related.
Oil level will only affect oil pressure when it's so low that the oil pump is sucking air.

[Brianmoooore]

Oil level light tells you that you are in danger of damaging your engine. Oil pressure light tells you that you just have.
Similar relationship between the coolant level light and the temperature gauge.

[mustard]

On a similar vain....

I have just replace my alternator (due to flickering dash warning lights as advised in another thread) now car starts and runs fine (warning lights no longer flicker... thanks guys!), BUT the engine check level light does not extinguish on the overhead check panel

I disconnected the battery before I started work, have I

A. Disturbed the sensor (is it in the alternator area?)

or

B. does the oil just need to settle back down in the sump (the car was run briefly before work commenced) so as the sensor may start reading properly again (its always worked fine)

thanks

[mustard]

Update.... took the car for a short run, parked it up on level garage floor for an hour or so, light cleared itself, all sorted