17 00 039 Venting cooling system and checking for leaks (Z3 M54)

WARNING: This page is about a different car, the 2002 BMW Z3 and 2001 BMW Z3. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: Danger of scalding! Only perform these tasks on an engine that has cooled down.

Check cooling system for leaks. Refer to 17 00 009 CHECKING COOLING SYSTEM FOR WATER LEAKS . Top up coolant. Refer to 17 00 005 DRAINING AND TOPPING UP COOLANT .

To ensure the cooling system is properly vented, it is absolutely essential to follow the steps below:

Open cap on coolant expansion tank.
Turn on ignition.
Set heating controller to maximum temperature.
Set blower to low level. This opens the heating valves and starts the auxiliary water pump.
Carry out filling procedure slowly.
Close vent plug (1) when bubble-free coolant emerges.

Fig 1: Closing Vent Plug

Courtesy of BMW OF NORTH AMERICA, INC.

Pour coolant into coolant expansion tank up to max. cold fill level. Marking (2) is then level with upper edge of coolant expansion tank.
Close coolant expansion tank.
Allow engine to warm up until thermostat opens.

Allow engine to cool down before checking coolant level. Coolant temperature must not exceed 30°C. If ambient temperature exceeds 30°C, allow engine to cool down at least to ambient temperature.

Carefully open sealing cap and check fluid level. Fluid level is O.K. when top edge of coolant expansion tank is between both markings (1 and 2) on float needle.

Minimum Cold Fill Level:
Top edge of coolant expansion tank is level with marking (1).
Maximum Cold Fill Level:

Top edge of coolant expansion tank is level with marking (2).

Fig 2: Identifying Min And Max Markings On Coolant Expansion Tank

Courtesy of BMW OF NORTH AMERICA, INC.

If necessary, top up coolant.

NOTE: The tank mark indicates the fluid level at approx. 20°C.

Use only recommended coolant.