[fullsmoke]

Hello,

2021 F90

Low coolant light came on tonight (low 30 degree ambient temps). Can I add normal coolant like Prestone (green color) concentrated solution and dilute with DI water?

And I noticed two different fill spots on top of the engine (near turbos)—which one is for filling? They both seem low…

Thanks,
FS

[pbonsalb]

Small tank is intercooler heat exchangers. Large tank is engine. BMW specified low phosphate silicate free coolant — the blue stuff it sells. A perfect aftermarket match may be Zerex G28. A close match that is on more parts store shelves is Zerex G05.

Since you can get the proper coolant delivered to you within days if you cannot source it locally, I see no reason to buy Prestone.

Blue may look green when it is on top of a yellow level indicator.

CORRECTION — see post below — Zerex G48 is the almost perfect match

[Mikiee]

Originally Posted by pbonsalb

Small tank is intercooler heat exchangers. Large tank is engine. BMW specified low phosphate silicate free coolant — the blue stuff it sells. A perfect aftermarket match may be Zerex G28. A close match that is on more parts store shelves is Zerex G05.

Since you can get the proper coolant delivered to you within days if you cannot source it locally, I see no reason to buy Prestone.

Blue may look green when it is on top of a yellow level indicator.

I had the same low coolant message a couple of weeks ago. Ended up going to the local AutoZone and picked up this pre-diluted Zerex G48. Needed to add 12oz or so to the engine reservoir and a smaller amount to the intercooler fill point. Color is blue....

[SigForLife]

There is an issue (with a related bulletin, I understand) with a plug on the top of the engine not sealing. They just had to replace mine because I got a low coolant light and they were able to find coolant leaking in the plug area.

[paulyboy123]

I seem to have an issue as well with low coolant warnings coming up. I cannot find a single leak though anywhere within the engine bay. Had to top up twice within a two month period already. Temps in my area are around 30-40 degrees now during this time of the year.

[AP]

If still under warranty get the dealer to check. Plenty of reports here in the g30 threads about leaks ( myself included) . In my case the reservoirs had tiny leaks and were replaced under warranty. It sure if the m5 shares the same parts. But see people are getting robbed off by dealers that it's normal. It's not as it's a sealed system