Cooling system characteristics (BMW 3 Series E21)

The car uses a liquid engine cooling system with forced circulation of liquid, with an expansion tank.

Radiator

The radiator is a Behr tubular-finned type with transverse circulation. On cars with automatic transmission, an oil cooler is built into the right radiator tank.

Expansion tank valve opening pressure, kg/cm²:

• safety: 1^+0,15_-0,10.
• inlet: up to 0.9.

Water pump

The water pump is a vane type centrifugal pump. It is driven by a V-belt from the crankshaft pulley.

The gap between the impeller and the cover ring of the pump body, mm: 0.6±0.2.

Thermostat

Temperature of the main valve opening start,°C: 80±1.5.

Main valve piston stroke at 80±1.5°C, mm: 8.

Water pump drive belt

Brand and type: Continental SPZ 9.5 950 La Z, Kleber Venuflex AV 10 940 or Gates 6218 MC.

Fan

Prior to the 1980 model year, vehicles were equipped with a five-blade, two-speed electric fan driven by an electric motor, which was turned on and off by the electric fan switch.

Brand and type of fan: Bosch IPL 12V.

Fan diameter, mm: 366.

Since the 1980 model year, vehicles have been equipped with a nine-blade fan driven by a Holset sliding viscous clutch.

Fan brand: Walker.

Fan diameter, mm: 420.

Electric Fan Switch Sensors (up to 1980 model year)

Coolant

Capacity of engine cooling and cabin heating systems, l: 12.

The coolant used is a mixture of distilled water and antifreeze in a ratio of 60 and 40% (at temperatures up to -25°C).

Replacement frequency: every two years of operation.

[The original material is located on the website: «BMWMan»]