[Unspec]

I seem to be getting the dreaded "Low Oil, add 1 quart immediately etcetc" message, but only when the engine is cold. Once the engine is warm and everything is humming along, I'll measure the oil level again and it'll be perfectly fine, right at the max line. Is this something to be concerned about, or an artifact of being cold? It's around 25*F at night here, and the oil is Liquid Moly High Tech 5W40. I changed the oil around the beginning of this month, and had some left over oil (300ml or so) so I added that in just to be sure. Thanks for any insight into this issue.

BMW, give us back our dipsticks!

[wcr3d]

This seems to go back to the E60 where they first started with the sensor only setup.
Condensation seems to throw off the sensor, once dissipated/warmed all is fine.

[BurrNinja]

Ignore this post.

[Unspec]

Originally Posted by BurrNinja

When colder oil gets thick, it will thin out when up to temp showing full status. Try running a 0w40 next time in winter and see what it displays. Its like my transmission, it shifts slow when its cold but once warmed up smooth as can be. Also what above user posted, condensation is a pain in winter. Drive a bit when you can for 15 to 30 minutes a lot of condensation will evap out of the system, if short trips it will build up faster.

Sorry I'm a bit confused by what you're saying. As far as I remember from my physics courses, viscosity and volume have no relation, so why would cold 5W40 occupy a different volume compared to hot 5W40?

[BurrNinja]

Hell now that I really think about it, maybe it could be sensor issue. Ignore that I realized yes that is true. That sensor can be false reading due to moisture. Just running my thoughts down.

[Surly73]

There will absolutely be a volume change between cold and hot, you can see this every day if we had a dipstick. But, it will not mean the difference between "add oil immediately" and being at "max" on the electronic level sensing system.

Personally, I would suspect the sensor. It could be faulty or covered in varnish or sludge depending on the maintenance history and type of oil chosen. I see you're running LM now - is the full history known? (you don't mention how long you've had the car).

I can attest that it is not expected behaviour due to "the cold". 25F isn't all that cold where I am and I haven't seen these kind of issues at -20F.

[Unspec]

Originally Posted by Surly73

There will absolutely be a volume change between cold and hot, you can see this every day if we had a dipstick. But, it will not mean the difference between "add oil immediately" and being at "max" on the electronic level sensing system.

Personally, I would suspect the sensor. It could be faulty or covered in varnish or sludge depending on the maintenance history and type of oil chosen. I see you're running LM now - is the full history known? (you don't mention how long you've had the car).

I can attest that it is not expected behaviour due to "the cold". 25F isn't all that cold where I am and I haven't seen these kind of issues at -20F.

Sorry I was probably a tad unclear. I was just referring to viscosity, as in "cold viscosity" and "hot viscosity", not the referring directly to the temperature.

I've owned the car for the entire life of the car, and used to take it in to the dealer because I had the extended care package or whatever it's called. Now that it's expired, decided to do my own change. I'd say it has been maintained pretty well.

I'm taking the car in to the dealer for some other diagnosis (transmission pan has some oily residue, so it might be leaking), so I'll ask around. Since adding the 300 or so ml of oil though, I haven't had the warning come up again. So maybe I was just low by a tad? Who knows.

[BurrNinja]

Originally Posted by Surly73

There will absolutely be a volume change between cold and hot, you can see this every day if we had a dipstick. But, it will not mean the difference between "add oil immediately" and being at "max" on the electronic level sensing system.

Personally, I would suspect the sensor. It could be faulty or covered in varnish or sludge depending on the maintenance history and type of oil chosen. I see you're running LM now - is the full history known? (you don't mention how long you've had the car).

I can attest that it is not expected behaviour due to "the cold". 25F isn't all that cold where I am and I haven't seen these kind of issues at -20F.

Now the way that was worded makes sense, it was a thought. Thanks for making clear, I felt dumb as hell haha.

[Unspec]

Originally Posted by BurrNinja

Now the way that was worded makes sense, it was a thought. Thanks for making clear, I felt dumb as hell haha.

Yea sorry was a bit unclear. Meant to say that viscosity and volume have no relation in terms of temperature, but volume still definitely can change with temperature. Fluids typically get less dense as they heat up, and since mass is constant (ignoring evaporation losses), it means that volume is increasing.

[BurrNinja]

Originally Posted by Unspec

Yea sorry was a bit unclear. Meant to say that viscosity and volume have no relation in terms of temperature, but volume still definitely can change with temperature. Fluids typically get less dense as they heat up, and since mass is constant (ignoring evaporation losses), it means that volume is increasing.

All good, sometimes wording certain things I get brain farts. Glad someone else could clear it up. Id rather try to help people and learn as much as I can. Hopefully your issue gets resolved, I know how it feels to chase a problem that knowledge is lacked in that area. Im chasing a problem with my suspension. Wish best of luck to you.