[510135]

Hello,
I have been keeping an eye on this. And I'm sure it's probably normal as I haven't had any CEL or anything for low coolant. (Just never experienced it with any other car)
I have been checking my coolant level every once in a while (always when cold), and topping it off to the max line, when dipping off the max line.
It only takes a very small amount of distilled water to bring it back to the max line , but it seems to never always stay at max, after re checking after 1000 or so miles.
Is it reasonable to expect a small amount of evaporation.
NB. It has never dipped below the Min level.
I left it probably 6 months/5000miles and it seems to have settled again between the min & max. I don't understand how a "closed" system can't maintain the max level. There is certainly no visible leaks.

[KGB_123_99]

Are you sure you are not overfilling it? If you do, the system will expel the extra coolant.

[510135]

Originally Posted by KGB_123_99

Are you sure you are not overfilling it? If you do, the system will expel the extra coolant.

Thanks for the reply.
No definitively not overfilling. Always to the line.

[KGB_123_99]

Originally Posted by 510135

Thanks for the reply.
No definitively not overfilling. Always to the line.

You shouldn't be losing any coolant on a new car unless there is a leak or your tank cap is not holding pressure.

Don't top off the coolant and drive to see if you will trigger a coolant level alarm. If you do, take it to the dealer. Best to let these issues come out of the woodwork while under warranty.

[JimCash]

BMW uses "sealed" coolant systems that are not exposed to the atmosphere (they use a "reserve" tank as opposed to an "overflow" tank) and therefore there should never be any loss of coolant under normal operation.

You are correct in checking it when cold - but the only thing to be aware of is the change in the surrounding "coldness" of that temperature.
When cold weather comes in the fall then your "cold" coolant level will be down slightly (even when in a garage) - and will rise again by the same amount next spring. Obviously ongoing w weather changes can also be a factor. So as long as you are taking that into account then you should be able to gauge as to whether you are loosing coolant or not. If you are then there is a minor leak in the system somewhere - and will have to be found via a pressure test process.

Cheers
Jim Cash

[martsro]

I'd suggest taking it in for service. I found mine to be loosing coolant very slowly as well. Actually had the low coolant warning at one point and found it was just below the level to trip the warning. Took it in and they found some corrosion caused by a small leak on one of the hoses from the tank. They replaced the hose and tank under warranty. So far so good since then.

[510135]

Originally Posted by martsro

I'd suggest taking it in for service. I found mine to be loosing coolant very slowly as well. Actually had the low coolant warning at one point and found it was just below the level to trip the warning. Took it in and they found some corrosion caused by a small leak on one of the hoses from the tank. They replaced the hose and tank under warranty. So far so good since then.

Will do! Thanks