Question about Coolant Refill Procedure

[Walt White Coupe]

So I've found very little information on-line and essentially nothing in the owner's manual about adding coolant if you get a "Low Coolant Level" warning. What I think is correct is that the "front" (#1 in picture) refill point is for adding coolant to the turbo charger inter-cooler system and that system is independent from the engine coolant system with a refill point at the right rear of the engine compartment (#2).

[IMG][/IMG]

So filling the (#1) inter-cooler system is pretty straight forward with a Min and a Max level indicator inside the expansion tank. I assume that this system does not trigger a "Low Level" alarm. And just as another point it seems that that system must have a small quantity of coolant in it since the difference between MIN and MAX is about a cup of coolant.

[IMG][/IMG]

Now when you open the right rear "engine coolant" refill cap there is nothing inside that refill tube to indicate "Low" or "Normal" levels of coolant.

So if my understanding of the systems is correct to this point, if you get a "Low Coolant Level" warning, I assume that's for the engine cooling system. If so, how do you know how much coolant to add to bring that coolant up to a normal level since there apparently is no FULL indicator that I could see.

[IMG][/IMG]

[Qsilver7]

Walt...this is an interesting topic. Looking at what the newtis.info website has to say...it looks like for the N63 b40 & b44...you fill coolant into the opening at the rear of the engine bay. See the illustration and text below as to how much:

N63 B40/B44 O 1 only:

Check coolant level when the engine has cooled down.
Adjust coolant level to (A) approx.110 mm – 160 mm below
the upper edge of the coolant filler neck. Use a tape measure where appropriate.

But for more info about the "vacuum coolant fill" procedure BMW uses for this engine...click this link: https://www.newtis.info/tisv2/a/en/f...check/1LIw3FH0

[Walt White Coupe]

Thank you so much. That's exactly what I was looking for.

[Qsilver7]

Looks like I'm gonna have to buy a ruler with at least inches & centimeter markings that I can use to stick down inside the filler neck. If I'm understanding the TIS correctly...if insert a measuring tool down inside the coolant filler neck...it should be dry from the top of the neck down to at least 10-16 centimeters (aka 110-160 mm or approx 4 inches - 6¼ inches).

Something new I guess...but perhaps using this "vacuum fill" set-up" will reduce the many call backs from incorrect "burping" issues with past generation BMWs.