17 11 509 Flushing radiator

WARNING: This page does not describe the selected car, but rather 15 other vehicles, including the 2005 BMW 330xi, 2005 BMW 330i, 2005 BMW 330Ci, 2004 BMW 330xi, and 2004 BMW 330i. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: If oil has penetrated the coolant circuit, you must flush the radiator and coolant expansion tank with cleaning agent, refer to appropriate BMW Service Operating Fluids. See OPERATING FLUIDS - MAINTENANCE & GENERAL INFORMATION

CAUTION: When working on the oil, coolant or fuel circuit, protect the alternator against contamination (not applicable to alternators with coolant jackets).
Cover alternator with suitable materials.
Failure to comply with this procedure may result in an alternator malfunction.

Separate coolant expansion tank

Remove radiator. See 17 11 000 Removing and installing radiator (M52TU, M54, M56)

Remove coolant expansion tank. See 17 11 100 Removing and installing/replacing coolant expansion tank (M52TU, M54, N42, N40)

Integral coolant expansion tank

Remove radiator. See 17 00 005 Draining and adding coolant (M54, M56)

Prepare approx. 2 liters of cleaning agent.
Fill radiator and coolant expansion tank and shake well. Wait a few minutes until oil has separated.
Drain radiator and coolant expansion tank.
Reinstall cleaned radiator and if necessary coolant expansion tank.
Fill entire cooling system (heating control to "warm") with hot water and thoroughly flush by changing water several times.
Check drained flushing fluid for traces of oil. If necessary, repeat Procedure 5.
After cleaning procedure, top up coolant. See 17 00 005 Draining and adding coolant (M54, M56)