[TCHBMW]

Hello,

I have a 2015 X3 which has ~58k miles on it. A few weeks back I brought it to the dealership for a routine oil change and 'Vehicle Check' prompted by the indicator in my X3

Everything from the vehicle check passed with flying colors. A week or so later I got an alarm for 'low coolant.' This alert only happened once, the alarm did not reappear on subsequent drives. Just to be safe, I checked the coolant level and it did appear to be low. I purchased BMW coolant (the concentrate) and combined it 50/50 with distilled water. I filled the reservoir with roughly a pint glass worth of 50/50 mix to get the coolant level between the MIN/MAX ring in the reservoir.

Since filling the reservoir, I've noticed when I stop the car after longer drives the coolant reservoir sounds as if there is boiling water in it (similar to a boiling tea kettle). When I pop the hood and touch the reservoir, you can feel the reservoir pinging with the boiling water.

I should note that there have been no issues with my engine temp overheating (at least the gauge has never indicated as much), no other service alarms have popped up, and when I check the coolant level (with a cooled down car, of course) it appears to be at the right level (see attached pic)

Should I be concerned with the tea kettle sound? Or is this just the result of filling the coolant to the appropriate level?

[Wgosma]

Well, the coolant is at or just above the boiling point in these systems, i.e. it's HOT.

Not certain about the audible sound - it's possible there might be some air entrapped in the cooling system, though that typically occurs after a system is partially or completely drained/refilled (as when a component needs replacement or periodic refresh with new fluid, etc.). Simply adding some coolant to bring level in expansion tank up should have no impact.

You could run the bleed procedure and that would eliminate any entrapped air; it's easy to do, see below.

Also, you can use the 'hidden menu' to display in real time the actual temperature, see if the system is operating above normal temperature for the coolant...it's possible tho not likely the car's thermostat is malfunctioning. Access hidden menu

. (you need to 'unlock', the 'code' you enter to unlock is the sum of the last 5 digits of car's VIN number)...then you can access menu for Coolant Temp and other parameters.

Coolant bleed (this is for 6 cylinder motor, I think 4-cyl. same procedure)
Bleed cooling system! Note:
Do not open the coolant expansion tank cap during the bleeding procedure.

Switch on the low-beam headlights to perform the bleeding procedure. If the low-beam headlights are not switched on, the ignition (Terminal 15) will switch off automatically after a certain period of time and interrupt the bleeding procedure.


Connect battery charger.
Switch the ignition on.
Switch on low-beam headlight.
Set heating to maximum temperature. Take back blower to smallest stage.
Driving experience switch must not be set to ECO PRO!
Press accelerator pedal for 10 seconds to floor. Engine must not be started.
The bleeding procedure was started by pressing the accelerator pedal and takes approx. 12 min. (the electrical coolant pump was activated and switches off automatically after approx. 12 min).
Then adjust fluid level in the coolant expansion tank to maximum.
Check the coolant system for leaks.
If the ventilation has to be performed again, deactivate DME completely (remove ignition key for approx. 3 minutes). Then repeat from point 3.

[6MT_Addict]

Originally Posted by TCHBMW

Hello,

I have a 2015 X3 which has ~58k miles on it. A few weeks back I brought it to the dealership for a routine oil change and 'Vehicle Check' prompted by the indicator in my X3

Everything from the vehicle check passed with flying colors. A week or so later I got an alarm for 'low coolant.' This alert only happened once, the alarm did not reappear on subsequent drives. Just to be safe, I checked the coolant level and it did appear to be low. I purchased BMW coolant (the concentrate) and combined it 50/50 with distilled water. I filled the reservoir with roughly a pint glass worth of 50/50 mix to get the coolant level between the MIN/MAX ring in the reservoir.

Since filling the reservoir, I've noticed when I stop the car after longer drives the coolant reservoir sounds as if there is boiling water in it (similar to a boiling tea kettle). When I pop the hood and touch the reservoir, you can feel the reservoir pinging with the boiling water.

I should note that there have been no issues with my engine temp overheating (at least the gauge has never indicated as much), no other service alarms have popped up, and when I check the coolant level (with a cooled down car, of course) it appears to be at the right level (see attached pic)

Should I be concerned with the tea kettle sound? Or is this just the result of filling the coolant to the appropriate level?

It's entirely possible it's boiling if someone mixed it in the wrong quantities, say 20 coolant / 80 water for example. I've never had mine make that sound even after a long drive with the engine temp around 118 C.

To confirm your ratio though you can just buy a tester like this one: https://www.amazon.ca/Prestone-AF-14.../dp/B000BOA9RY