17 00 039 Venting cooling system and checking for leaks (M54/M56)

WARNING: This page is about a different car, the 2003 BMW X5, 2002 BMW X5, and 2001 BMW X5. 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.

Necessary Preliminary Tasks:

Draining Coolant:

NOTE: Use only recommended coolant.

Adding Coolant:

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

Open cap (1) on coolant expansion tank.
Open vent screw (2).

Fig 1: Identifying Coolant Expansion Tank
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Switch on ignition.
Set heater control to maximum temperature.
Set fan to lower speed (so that heater valves open).
Fill with coolant slowly.
Close vent screw (2) when bubble-free coolant emerges.
Pour coolant into coolant expansion tank up to max. cold fill level. Marking (2) is then on a level with upper edge of coolant expansion tank.

Fig 2: View Of Cold Fill Level

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Close coolant expansion tank.
Allow engine to warm up until thermostat opens.

Checking coolant level:

CAUTION: Check coolant level at a maximum coolant temperature of 30° C.

NOTE: If ambient temperature exceeds 30° C, allow engine to cool down at least to ambient temperature.

Open cap carefully.

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:

Upper edge of coolant expansion tank is level with marking (1).

Maximum Cold Fill Level:

Upper edge of coolant expansion tank is level with marking (2).
If necessary, top up coolant.

Fig 3: Locating Minimum/Maximum Cold Fill Level
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NOTE: Tank mark indicates the fluid level at approx. 20° C.

Check cooling system for leaks. Refer to 17 00 009 CHECKING COOLING SYSTEM FOR WATER LEAKS .