17 00 039 Venting cooling system and checking for leaks (N62)

WARNING: This page is about a different car, the 2005 BMW 745i, 2004 BMW 745i, 2003 BMW 745i, and 2002 BMW 745i. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: Danger of scalding!
Open sealing cap only after engine has cooled down.

No vent plugs on radiator and thermostat housing.

Cooling system is vented while it is filled and during subsequent idle operation.

NOTE: Before filling, turn on ignition. Set blower to low level. Seat heating controller to maximum temperature. This ensures that the heater valves are fully opened and the auxiliary water pump starts up.

Important: The auxiliary water pump must deliver coolant in order to ensure fully venting!

Installation:

Use only recommended coolant.

Check cooling system for leaks. Refer to 17 00 009 Checking cooling system for leaks (N62) .

Illustration shows E65/E66:

Perform filling operation slowly.

Pour coolant into expansion tank (1) up to MAX mark.

Fig 1: Identifying Expansion Tank

Courtesy of BMW OF NORTH AMERICA, INC.

Start engine and run at idle speed for approx. one minute (cap open). Then adjust coolant level to MAX.

Close cap and run engine up to operating temperature until main thermostat opens. Check cooling circuit and drain plug for leaks.

Illustration shows E60/E61/E63/E64:

Perform filling operation slowly.

Pour coolant into expansion tank up to MAX mark.

Fig 2: Identifying Expansion Tank

Courtesy of BMW OF NORTH AMERICA, INC.

Start engine and run at idle speed for approx. one minute (cap open). Then adjust coolant level to MAX.

Close cap and run engine up to operating temperature until main thermostat opens. Check cooling circuit and drain plug for leaks.

IMPORTANT: The engine must be cooled down before the coolant level is checked. Coolant temperature must not exceed 30 °C. If ambient temperature is above 30 °C, allow engine to cool down to ambient temperature at least.
Check coolant level and adjust to MAX.

NOTE: Do not fill coolant expansion tank over MAX level as overfilling will cause the coolant to overflow.