Cooling system characteristics (BMW 3 Series E21)

The car uses a liquid engine cooling system with forced circulation of liquid using a rotary pump driven by a V-belt from the crankshaft pulley. The fan is pressed onto the front end of the water pump shaft.

Radiator

The radiator is a tubular-finned type with a safety valve built into the plug.

Opening pressure of safety valve: kg/cm:

• when pressure increases: 1^+0,15_-0,10;
• when pressure drops: up to 0.9.

Safety valve brand: Langeru et Reich or Behr.

Control pressure of safety valve, kg/cm²: 1.5.

On cars with automatic transmission, a radiator with an oil cooler is installed.

Oil cooler pressure, kg/cm²:

• control: 12.0;
• working: 8.0.

Water pump

The rotary water pump is mounted on the front of the cylinder block.

Clearance between the pump body and the impeller, mm: 1±0.2.

Water pump drive V-belt

Belt deflection when pressing with a finger on the middle of the belt branch between the pulleys of the water pump and generator, mm: 5-10.

Frequency of belt tension check: every 15 thousand km.

Fan

Fan - five-bladed. Diameter, mm: 360.

Thermostat

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

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



Brand: WaMer.

Coolant

Capacity of engine cooling and cabin heating systems, l: 7.2.

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.