[Tr4ckD4ys]

Hey guys! 2022 BMW X7 M50i here.

I finally find myself in the situation where I need the help of the fellow forum members.
I did a trip to Grand Rapids, MI this weekend and after the car was parked overnight, I just got back to it to get something from the trunk. When I opened the door, a yellow error message greeted me "Check coolant level". I went in and check both reservoirs and they're both bone dry. Like, not low, but actually bone dry.

Now, first of all, the 150 mile drive here wasn't an issue at all. No errors, not temperature issues and no weird engine sounds or behaviors. I recognize the temperatures dropped from 70F on Thursday to 30F in Grand Rapids today, but that wouldn't turn the reservoir bone dry in my view.

Either way it's Sunday tomorrow and everything is closed so I can't buy BMW coolant and can't have a shop check it out until I'm back home. I looked at the manual but wasn't able to locate the specs. Anybody knows what I can buy at the local Walmart/autozone to pour in there to get me back home?

Thanks so much!

EDIT: Went to three different stores to find HT-12 / BMW LC-18 spec coolant - to no avail. How does everybody feel about a little distilled water in 25F ambient temps?!

[themama]

Even if you have to wait get the coolant from dealership only. If you use anything else you may require coolant flush.

Now most importantly why did the coolant go dry. Look for an exterior leak, else it could be an internal leaking gasket.

[Qsilver7]

You can also use the older (blue) G48…see chart and diagram below…G48 or H12 (I’m sure I’ve seen G48 coolant sold at Walmart below…or do a google search for it). Good luck.

[Qsilver7]

Just checked…Walmart does sell Zerex G48 coolant:

[streborx]

Relieved to learn that the G48 formulation color coordinates well with my Msport brake calipers (lol).

[Qsilver7]

Another positive…g48 & ht-12 can be mixed…so you wont have to drain the system. But not sure what color you’ll end up with. What does mixing blue & pink make?

[streborx]

Originally Posted by Qsilver7

Another positive…g48 & ht-12 can be mixed…so you wont have to drain the system. But not sure what color you’ll end up with. What does mixing blue & pink make?

Valvoline (Zerex) markets an HT-12 / BMW LC-18 coolant formulation under the tradename Frostox in Europe, but I've not found it available anywhere in the U.S. Maybe because it's green and would clash with pink, not to mention my brake calipers.