Charge cooler coolant

[Raif]

I noticed that the coolant in my low temp circuit reservoir (charge cooler?) and the high temp coolant reservoir basically looks like water. It's not an F8x it's a F36 but thought this would be a good place to ask.

I'm assuming the coolant in there should be the BMW green coolant in both of the coolant tanks right? Car is on 25k with full BMW service history so scratching my head a bit. A photo of the coolant below. I've got some of the correct coolant (the charge cooler tank is low anyway) but wanted to see what should be in there first. Can't find anything definitive online

This is what's in there (pretty much clear)

 

[Zarakoff]

It looks like just water i would dip my finger in and touch my tongue if it’s sweet then there antifreeze in there . I’d still just flush the tank and put the recommended stuff in

 

[Raif]

It looks like just water i would dip my finger in and touch my tongue if it’s sweet then there antifreeze in there . I’d still just flush the tank and put the recommended stuff in

But it should be visibly green right? Surely that's way too diluted. I'm not even sure if the recommended stuff is same the stuff as on the E series cars which is what I have or if its meant to be like this?

BMW will only quote a coolant part number

 

[S18M3]

That should certainly be green. Have you taken that sample from the main expansion tank or the charge cooler tank. Didn’t realise the F83 had the separate charge cooler tank too

 

[Raif]

That should certainly be green. Have you taken that sample from the main expansion tank or the charge cooler tank. Didn’t realise the F83 had the separate charge cooler tank too

Cheers thats what I needed to know. I have that coolant so will sort it out.

Both the main tank and charge cooler tank had exactly the same dilution/colour. The charge cooler tank ("low temp circuit") is at the back of the engine bay on an S55 I think. On my B48 engine its at the front of the engine bay near the main tank ("high temperature circuit").