Cooling system (BMW 5 Series E12)

Coolant temperature gauge

The pointer scale has two colored zones.

Blue Zone: the engine is not warmed up, you can move at low speed and at medium engine speeds.

Red zone: The engine temperature is very high. The pointer may reach this zone and even remain there for some time when the ambient temperature is high and the engine is operating under heavy loads. If the pointer remains in this zone for a long time, the following may be the reasons:

• low coolant level: add coolant to the radiator, check the tightness of the radiator cap, cooling system hoses and radiator;
• loose or worn fan drive belt;
• clogged radiator fins;
• incorrect ignition timing adjustment;
• on 520 model vehicles with automatic transmission, check the operation of the additional electric fan.

At normal engine operating temperature, the gauge needle is between these colored zones.

Cooling system

The coolant contains long-lasting antifreeze and an anticorrosive additive. The fluid should be replaced every two years. Check the antifreeze content at the beginning of winter. The percentage of each type of antifreeze is specified by the manufacturer.

It is recommended, as when the car leaves the factory, to use a coolant with a freezing point of at least -25°C.

When replacing the coolant, it is recommended to check the tightness of the system hoses (also check every 15,000 km).

Warning: Check the coolant level periodically when the engine is cold. Add cold water only when the engine is on the deck.