Webweaver

I have just changed the water temperature sensor on my 545i (2004). Obviously I lost some coolant enough for low coolant warning, I need to top it up, but don’t want to do a full coolant change. The coolant is currently reddish in colour. Can I use any type of ready mixed coolant to top up? I know there are some types you can’t mix, but unsure which.

twh

Sounds like not BMW coolant is in there - at least what I've gotten in BMW jugs is blue-ish. Not that this is necessarily wrong, but it isn't what I'd expect. Main problem is you don't know what's in there and what you are going add. If you assume or know it is the right stuff, then adding some BMW coolant to top it off is fine even if a different color.

donpb

I previously had yellow, and it mixed fine with blue.

Webweaver

Thanks for this