[admranger]

Originally Posted by ezaircon4jc

I never understood that as the cooling system is a sealed system. The only way to "use" coolant is due to a leak somewhere in the system.

Agreed. It's a pressurized system. If coolant is disappearing, there's a leak and that's unacceptable.

[Chappers 71]

Evaporation,

Does Coolant Evaporate? (All You Need To Know Explained!)
by Hank Brown December 15, 2021 Categories Cars
Many car drivers notice that their coolant is disappearing. This is not good for car drivers because coolant is vital to the engine of all vehicles. If you have the same observation, let us talk about the reason behind it.

So does coolant evaporate? The answer is yes, coolant does evaporate naturally. This is the explanation why you might notice that your coolant is disappearing even without leakage.

[Chappers 71]

Originally Posted by admranger

Agreed. It's a pressurized system. If coolant is disappearing, there's a leak and that's unacceptable.

So is a central heating system but one still needs to top off the boiler once or twice a year

[Joe-BMW33]

Originally Posted by Chappers 71

So is a central heating system but one still needs to top off the boiler once or twice a year

Apples and Oranges Chaps.

[Chappers 71]

Originally Posted by Joe-BMW33

Apples and Oranges Chaps.

Well I’m happy to believe that a little coolant is lost due to evaporation

[Joe-BMW33]

Originally Posted by Chappers 71

Well I’m happy to believe that a little coolant is lost due to evaporation

Yes, but not over the course of a few months. 2-3 years maybe.

[Chappers 71]

Originally Posted by Joe-BMW33

Yes, but not over the course of a few months. 2-3 years maybe.

Granted not over a few months but I’ll take the 200ml the G31 has ‘used’ over the last 14 months as ‘evaporation’ & just check it once in a while as I normally do.

[Pierre Louis]

As I've said elsewhere, all my cars seem to need a little coolant refill perhaps once every 1-2 years. It seems to be from the fact that coolant when hot, and it gets hot allegedly for emissions systems to operate, that goes into the overflow tank and lets off pressure/steam to a small extent.

The local BMW dealer keeps a jug of coolant as well as windshield washer fluid handy to top-up customer cars that casually drive in.

[Joe-BMW33]

Originally Posted by Pierre Louis

As I've said elsewhere, all my cars seem to need a little coolant refill perhaps once every 1-2 years. It seems to be from the fact that coolant when hot, and it gets hot allegedly for emissions systems to operate, that goes into the overflow tank and lets off pressure/steam to a small extent.

The local BMW dealer keeps a jug of coolant as well as windshield washer fluid handy to top-up customer cars that casually drive in.

Agreed, 1-2 years. The M550 has commonly know coolant leaking issues where people get the add coolant message every few months or a few thousand miles. The dealer and manual will tell you this is normal consumption. They did it to me. Then the leak becomes greater and easily diagnosable and they replace old parts with updated parts. Happened to me, not one coolant low message since.

That’s all I’m saying. Push back on the dealer.