Draining and Topping Up Coolant

Warning: Danger of scalding!

Only perform this work after engine has cooled down.





Draining coolant
Unfasten cap on expansion tank.





M62
Unfasten cap on expansion tank.
Release vent screw.





If necessary, remove front underbody protection from units.
Unscrew drain plug at bottom of radiator.
Installation: Replace seal.
Tightening Torque, refer to Cooling System, Specifications.
Drain, catch and dispose of coolant.





M62
It necessary, remove front underbody protection from units.
Cars with automatic transmissions: Turn hose plug (1) to left and detach towards bottom.
Cars with manual transmission: Remove drain plug at bottom of radiator.
Drain, catch and dispose of coolant.





Unfasten drain plug(s) on engine block.

M62
Remove drain plugs on left and right of engine block.
Installation: Replace seal.
Tightening Torque, refer to Cooling System, Specifications.
Drain off and catch coolant.

Recycling
Dispose of drained coolant.
Observe country-specific waste-disposal regulations.





Top up coolant!
Slacken vent plug (2) on expansion tank.

On cars with latent heat accumulators, do not turn on ignition when filling cooling system.
Follow venting procedure specified, refer to Heating and Air Conditioning.





On vehicles with M52 engines, also unfasten additional vent screw.





Note: Turn on ignition. Set heater control to maximum temperature. Set blower to low level. This opens the heating valves and sets the auxiliary water pump in operation.
Perform filling operation slowly.
Fill up expansion tank fully and wait until bubble-free coolant emerges, from vent plug. Tighten down vent plug.

Note: Use only recommended coolant.





M62

Note: Turn on ignition. Set heater control to maximum temperature. Set blower to low level. This opens the heating valves and sets the auxiliary water pump in operation.

Perform filling operation slowly.
Fill up expansion tank fully and wait until bubble-free coolant emerges; from vent plug. Tighten down vent plug.

Note: Use only recommended coolant.

Note: Vent cooling system and check for leaks, refer to Bleeding Cooling System and Checking For Leaks.