Oil light

Ct Midnite haute in die Tasten:

The oil indicator light on this model frequently drives me nuts. Possible reasons for an oil alarm are:

1. Oil level too low
2. Car does not stand on an even surface when you start the engine
3. Oil is very hot and therefore has very high viscosity
4. bad oil sensor design
5. bad oil sensor design
6. some electronic fuss in the instrument cluster.

My advice: Forget about that damn thing and check oil with the dip stick once a month and/or after serious full throttle driving.

Frank

Most likely that the non BMW dealer drained down the oil when the ignition was on. Oil loss while running would be a major fault, so the light stays on until a BMW dealer resets the maintenance computer. This is not the same as the service indicator.

No it doesn't. As soon as you refill the oil the light goes out on its own. There is nothing that needs to be reset. This is a 1991 for crying out loud...

-Fred W

I think you meant *low* viscosity.

-Fred W

You are correct. On an E30 the check control oil light refers to "oil level" not oil pressure which would be indicated in the instrument cluster.

Since they are expensive you may want to take it out and see if it can be cleaned up or something. Here is the parts breakdown so you can see what you are up against:

-Fred W

Which, by the way would not cause the "low oil level" warning light to come on. ;-)

-Fred W

Malt_Hound haute in die Tasten:

I do not know if you own an E30 325i convertible with check control unit above the rear mirror, but I do own such a car (mine was built in the beginning of 1992), so does the original poster.

You seem to believe that the oil level warning light in this check control is able to indicate a low oil level - and nothing more. I use my 325i since six years and I have always had trouble with erratic messages of the oil warning light. My conclusion is: it is bad design and one should live with it and check the oil level once a month manually. One also has to be careful when going on a long high speed trip after some weeks of short range city traffic use. Due to many cold starts it is possible that humidity from outsides contaminates the oil circuit and increases the amount of fluid (not oil) in the oil pan. Once the engine gets really warm, this humidity vanishes very quickly, which can cause a surprising drop of the oil level. Therefore my advice: If you had your car in traffic situations for weeks which never allowed the engine to get throughoutly hot and you add a stretch of high speed driving, check the oil level manually at the first tank stop after that.

An accurate control of the oil consumption of a given engine does not only protect you from damages due to an oil shortage, it also is a good indicator to upcoming engine troubles such as piston ring or valve seal wear als well as any lakage. Unfortunately the E30 check control is not sufficient for that accurate control.

Frank

Owned, as in past tense, an '87 325iC.

Correct. I know this because I have access to service manuals that show diagrams of what sensors go to the check control.

Good advice, no doubt.

I agree. It is a binary indicator and not what I would want for knowing what is happening with my oil level. That is where the dipstick comes in handy.

-Fred W