17 00 039 Venting Cooling System and Checking For Water Leaks

17 00 039 - Venting cooling system and checking for water leaks (M57TU, M57T2)





Warning!
Danger of scalding!
Only perform this work after engine has cooled down.





Important!
Protect alternator against coolant.
Cover alternator with suitable apparatus (risk of damage).

Filling and venting instructions with auxiliary heater.
- Switch off engine, coolant temperature ≤ 40°
- Open cap on expansion tank (AGB)
- Open vent screws.
- On EGR cooler thermostat
- On coolant return pipe
- Switch ignition on
- Seat heating to maximum temperature and fan to low speed (heater valves are opened and auxiliary water pump starts up)
- Add coolant slowly
- Close vent screws after coolant emerges or after filling up to max. cold fill level
- Fill expansion tank to maximum cold fill level
- Start engine and run at idle for 5 minutes (top up coolant to maximum cold fill level if required)
- Close cap on expansion tank, press accelerator pedal several times to approx. 2500 rpm
- Open cap on expansion tank, run engine at idle for a further 5 minutes (bubble-free coolant emerges at vent line in expansion tank)
- Fill to maximum cold fill level
- Top up expansion tank with an additional 250 ml
- Close expansion tank cap

Additional instructions for cars with optional extra independent heating:
- Switch off engine
- Run independent heating for approx. 2 minutes
- Start engine and run briefly at idle
- Press accelerator pedal twice up to approx. 2500 rpm
- Open cap on expansion tank and add coolant up to max. cold fill level
- Top up expansion tank with an additional 250 ml
Check cooling system for leaks Component Tests and General Diagnostics.