[Luky]

So I got a low coolant error and bought a gallon of zerex G48 premixed coolant to top it off. The first problem I had was locating the fill for the radiator. At first I added to the coolant bottle in the front center as it was showing a little low, but later I got the low coolant level again. Apparently this is only for the air/water inter-coolers for the turbos.

Then I looked online to try and determine where to add radiator coolant, but the pics/video I found for a 550i showed a coolant tank in the drivers side front corner behind the headlight. My car does not have a tank there (only what appears to be a computer module, which interestingly enough has cooling lines going to the inter-cooler reservoir). I noticed another high pressure cap on the inside fender near to the brake cylinder and after opening it had to guess that this was the radiator overflow reservoir. I ran the car with this cap off and saw coolant circulating, but there is no indicator for level. I added about a pint, with it running and turned on the heat inside and kept it running until it warmed up to about 150F. I kept adding coolant mix until it reached a flat "ledge" I saw inside the tank (might be a level marker?) and then buttoned it up. Have not received another low coolant error, but when I checked it again yesterday, it was several inches below where that little flat area is and I am wondering if I should add more coolant mix? It really sucks that BMW/manual does not support something as simple as adding coolant to your car...

[Luky]

Bueller? Bueller?

[wcr3d]

Have you tried newtis?

[Luky]

Originally Posted by wcr3d

Have you tried newtis?

Nope. Was not aware of that website. Thank you.

Found:
Adding coolant:

Cooling system must be filled with a vacuum filling unit only!

Use only recommended coolant.

Observe mixture ratio.

Observe filling capacities.

There is a slightly complicated venting procedure, then it shows a diagram of the filler neck and has the text:

When the engine has cooled off, check the coolant level and adjust it to (A) approx. 150 mm below the upper edge of the coolant filler neck. Use a tape measure where appropriate.

How stupid is that? Use a tape measure to check the level... I am not impressed with this level of German "Engineering" and I'm an Engineer...

[AZ_Bmw_550]

Yep, it's the only car I've ever owned that requires a tape measure to install coolant. Very DIY friendly...

[doodlebro]

I'm confused. Is there no overflow reservoir on these cars?

[Walt White Coupe]

This is from my 6 Series with the same engine.