Coolant: Service and Repair

Draining And Topping Up Coolant

Warning! Danger of scalding!

Only perform these tasks on an engine that has cooled down.

Recycling
Catch and dispose of drained coolant.
Observe country-specific waste-disposal regulations.

Draining Coolant:
Separate Coolant Expansion Tank (M62):





Open cap on coolant expansion tank
Slacken vent plug on coolant expansion tank.

Integrated Coolant Expansion Tank (M54 / M57)





Open cap (1) on coolant expansion tank.
Slacken vent plug on coolant expansion tank.

M62, M54 and M57
Remove reinforcement plate.

Caution! The section "Removing and installing reinforcement plate" contains important installation instructions, refer to Transmission and Drivetrain.





Release screws. Remove underbody paneling (1).

M62:





Open drain plug at bottom of radiator.
Drain, catch and dispose of coolant.

Installation:
Replace seal.
Tightening torque, refer to Specifications, Mechanical.

M54 and M57:





Open drain plug (1) at bottom of radiator.

Manual Transmissions Only:
Open drain plug (2) on coolant expansion tank.
Tightening torque, refer to Specifications, Mechanical.





Open drain plug on right of engine block.
Drain, catch and dispose of coolant.

Installation:
Replace seal.
Tightening torque, refer to Specifications, Mechanical.

Adding Coolant:

Note: The tank mark indicates the fluid level at approx. 20 deg. C.

Use only recommended coolant,

1. Turn on ignition.
2. Set heating controller to maximum temperature
3. Set fan to low setting. This opens the heating valves and starts the auxiliary water pump.
4. Perform filling operation slowly.
5. Pour coolant into coolant expansion tank up to max. cold fill level.
6. Close vent plug when bubble-free coolant emerges
7. Close coolant expansion tank.

Vent cooling system and check for leaks.