What is the right coolant level?

[PJayUK]

This has bugged me for a while...

The W220 manual says that the coolant level in the expansion bottle should be at the right level, however its not clear what "right" actually is. There is no real level indicator in the bottle apart from a little black knob on the inside about 3 quarters of the way up. So what is the correct level for coolant on these things?

Not losing any its just part of my regular paranoia checking routine!

 

[BlackC55]

There is a level sticking out inside when you take the cap off.

 

[PJayUK]

Ok thanks Ollie, I guess that must be the little black bump then on the inside! Not very easy to identify!

 

[PJayUK]

Do I have to use MB coolant to top it up or can I use something like Comma green coolant (that I already have!)