17 00 009 Checking cooling system for leaks (N54, N52K)

WARNING: Danger of scalding!

Only perform this work after engine has cooled down.

Protective measures/rules of conduct

Wear protective goggles
Wear protective gloves
Observe national/country-specific regulations

IMPORTANT: Risk of slipping due to coolant on the floor.

Danger of injury!

Catch and dispose of drained coolant in drip tray (1) and if necessary special tool 00 2 030 (universal hydraulic lifter).

Recycling:

Observe country-specific waste-disposal regulations.

Fig 1: Lifting Drip Tray Using Special Tool (00 2 030)

Courtesy of BMW OF NORTH AMERICA, INC.

Checking pressure drop in cooling system

Open cap on coolant expansion tank. Fit special tools (1) 17 0 101 and (2) 17 0 113.

Build up GAUGE PRESSURE and wait approx. 2 minutes.

Cooling system is impervious to leaks if pressure drop is max. 0.1 bar.

Fig 2: Checking Pressure Drop In Cooling System Using Special Tools (17 0 101) And (17 0 113)

Courtesy of BMW OF NORTH AMERICA, INC.

Checking pressure relief valve in cap

NOTE: While the vehicle is driven at high outside temperatures, the design may cause the pressure relief valve in the cap to open slightly and air together with dissolved coolant to escape. This coolant vapor condenses on the surface of the expansion tank and leaves traces when the vehicle has cooled down. These traces do not indicate whether the cap is defective or not. When the vehicle has been parked up for an extended period of time, the residual escaping coolant can cause the pressure relief valve in the cap to stick; therefore check the cap again 2 to 3 times.

Replace the cap only after you have checked three times and there is an incorrect opening pressure.

Checking pressure relief valve in cap

Screw cap (1) onto special tool 17 0 114.

Build up pressure with special tool (hand pump) 17 0 101; observe pressure gauge to ascertain when opening pressure is achieved.

Compare OPENING PRESSURE of pressure relief valve.

Fig 3: Checking Pressure Relief Valve In Screw Cap Using Special Tool (17 0 114)

Courtesy of BMW OF NORTH AMERICA, INC.