Checking the density of the coolant (BMW 7 Series E32)

Before the onset of the cold season, it is necessary to check the concentration of the coolant, especially if water was added to the cooling system.

Warm up the engine until the upper radiator hose is warm.

Carefully open the expansion tank cap.

Caution: Do not open the cap when the engine is hot.

Fill the hydrometer with coolant and determine its density (it is often given in degrees of freezing temperature). Typically, the freezing point should be around -35°C. This corresponds to a 1:1 ratio of antifreeze to water in the coolant.