Coolant level too low --> but only when its cold

okay guys so recently I started receiving a message on my dash saying that my coolant level is too low, but for some odd reason it only comes on when the engine is cold (over here in Winnipeg, MB it gets to be about -25 to -30 on average with windchill) like after I drive the car for a bit and the engine is warmed up, every subsequent stop and restart of the car, the warning message does not come on, only comes on when I leave the car parked outside overnight and when I start it up in the mornings to get to work. I don't notice any leaks or anything, and my car was only purchased 4 months ago from the dealership so I would have assumed that they would have topped it off.... does anyone have any ideas as to what is going on? any input is greatly appreciated.

Got the coolant level low message for the first time myself a month ago and it just so happens it was pretty cold that day. I had the car in for maintenance on that day and they just topped off the coolant. No errors since. Just top it off and you might not have an issue anymore...

Originally Posted by jim165

Got the coolant level low message for the first time myself a month ago and it just so happens it was pretty cold that day. I had the car in for maintenance on that day and they just topped off the coolant. No errors since. Just top it off and you might not have an issue anymore...

thanks for the input, I might need to bring it into the dealership to have them top it off, hopefully they don't charge me an arm and a leg just to do that as I recall that bmw uses a special phosphate free type of coolant..... but does anyone else have any inputs as to why it happens only when the engine is cold? would it be some sort of ticking time bomb before something major goes and its a $1000 plus repair??

My 3 series just needed about a cup when the weather turned cold...it has no leaks or issues. If you only need to add a cup or 2, why not used distilled water?

Fluids expand and contract with heat it's that simple. Top off the coolant level when the engine is cold and you shouldn't have any more issues unless there is a leak that you aren't seeing

Originally Posted by l1tech

Fluids expand and contract with heat it's that simple. Top off the coolant level when the engine is cold and you shouldn't have any more issues unless there is a leak that you aren't seeing

Ditto!

If you only need to top it off (adding couple of cups of coolant), you can pour distilled water.

Get that coolant check on how low can it go before it freeze. Dealer or even auto-part store has the instrument to do it.
You may have to swing 60-40 on coolant-water mix instead of 50-50 with temp that low and parking outside (not in the garage).

Do it yourself with BMW coolant and keep the coolant in the trunk in case you ever do need it.

I would get some BMW coolant and top it off. Up there I would run about 65% coolant to lower the low temperature safety point for freezing.

Be careful if you are going to keep coolant in the trunk. If it spills and your MPM hasn't been moved from the normal position under the spare tire you will have a lot more to worry about than a low coolant light. If you decide to carry the coolant I would enclose it in a 6mil or 7mil heavy duty plastic bag, which auto parts suppliers use to ship gallon jugs of coolant via UPS or USPS.

And if your cooling system hasn't been flushed and filled with new coolant in the last 3 years that should be on your maintenance list for this summer.

this happened to me recently - than i realized that its possible the collant froze and when the engine gets hot it unfreezes

i left it alone since the warning went away

no more warnings unless its cold (overnight) engine so it must be the coolant freezing IMO

Happens all the time. Top it off.

Originally Posted by watchurself

this happened to me recently - than i realized that its possible the collant froze and when the engine gets hot it unfreezes

i left it alone since the warning went away

no more warnings unless its cold (overnight) engine so it must be the coolant freezing IMO

Coolant mixed 50/50 protects down to -34 deg. If your coolant actually froze, you would have more problems than just a warning message.

Originally Posted by legend700

Coolant mixed 50/50 protects down to -34 deg. If your coolant actually froze, you would have more problems than just a warning message.

+1

You need to check your antifreeze ratio, or if you can't do it have any reputable repair shop check it for you.

You will see some freezing of thin lines or narrow water passages first, before your block freezes hard enough to expand and crack it. But you can't take a chance ruining your engine. If you end up not driving the car for a few days and get a really bad cold snap your engine could be finished.

In fact I would consider bringing your ratio of coolant up to 65%, which should make you good to about -50F.

A 60/40 mix is good for -62F as per BMW coolant container.

Originally Posted by legend700

A 60/40 mix is good for -62F as per BMW coolant container.

+1 You are correct, that is what BMW states.

I was extrapolating and industry average with some coolants claiming -55F with 70% coolant, but BMW does indeed claim -62F with 60/40.