Taken from my post on FB:
Coolant Maintenance
Amongst the checks you should regularly do on your car, is the coolant. To check the level, top up and to check the condition of your coolant, follow the following guide.
To Check Coolant Level:
On the side of the coolant bottle, there are embossed markings that shows
KALT/COLD
MAX
and a triangle pointing downwards which points to the waist of the bottle. See the attached pic. This indicates the maximum level of coolant when cold.
There is a corresponding MIN marking below the waist of the bottle about 1" below the max marking. It is a little harder to see.
To Top Up The Coolant:
When topping up, it is recommended that you use the original BMW coolant from any BMW workshop or stockist.
In the absence of BMW coolant then any branded compatible coolant will do. These are available at any gas station, workshops, spare parts shops and DIY stores.
An original BMW 1.5 lit bottle of coolant is about RM35 from a popular local stockist.
Do not use or mix the orange, pink or red colored coolants. The original is blue. But some parties believe that yiu can mix blue and green coolant. But my recommendation is to stay with the same color that is already there.
In the absence of coolant, in an emergency, clean water will do the job when topping up.
In any case, the SC will check and top up the coolant if required during service visits. Typically you shouldn't need to top up the coolant between service visits. But there can be a slight drop in the coolant level.
However, if your coolant level is very low, I would be suspicious if there's a leak somewhere.
Condition of Coolant:
Examine the coolant. It should appear clear.
- A rusty or cloudy appearance indicate problems of rust or contamination of the cooling system.
- Evidence of an oil film indicate engine oil has leaked into the cooling system.
- Evidence of a layer of carbon on top of coolant indicate that there may be a leaking gasket.
- White crystals on the outside indicate a leak.
Completely flush your cooling system and refill with fresh coolant every 3-5 yrs or 50,000km.
Dispose of your coolant in the proper manner. Engine coolant contains the anti-freeze ethylene glycol. It is sweet and is toxic to humans and animals, and pollute the environment.