Attention!
- Coolant replacement should be carried out only on a cold engine, due to the possibility of getting burned by its vapors.
- Protect the generator from contamination.
- Place a container to collect the coolant at the drain point.
- The coolant should be filled through the expansion tank of the cooling system and brands strictly certified by the company «BMW».
- The drained coolant must be disposed of.
- The mark on the expansion tank of the cooling system shows the maximum liquid level in the system at a temperature of 20°C.
Draining the coolant from must be carried out in the following order.
Prepare a container for draining the coolant and a clean rag. Unscrew the plug (valve cover) (1, fig. 5.162) on the expansion tank of the cooling system.
Loosen the bleed screw on the radiator expansion tank, if equipped, and remove the front engine accessory guard.
Remove the stiffening plate, unscrew the drain plug in the lower part of the radiator of the cooling system and the plug (1, fig. 5.163) drain hole on the cylinder block (on the right side). Drain the coolant from and send it for recycling.
Replace seal gasket (M14x1.5) cylinder block and tighten it to 25 Nm (2.5 kgf·m).
Replace the drain seal at the bottom of the radiator and tighten its plug to 8.0 Nm (0.8 kgf·m).
Turn on the ignition. Set the air conditioner control to the maximum temperature, the fan control to the lowest speed. At the same time, the valves of the heater block open and its additional pump starts to work.
Remove the screw to bleed air from the engine cooling system. Line the filler neck with a clean rag.
Slowly fill the coolant through the neck of the radiator expansion tank to the maximum mark. Wait. until coolant comes out through the radiator expansion tank vent without air bubbles.
Wrap the cork (M8) vent hole on the expansion tank of the radiator with a torque of 8.0 Nm (0.8 kgf·m). Close the expansion tank of the cooling system. Remove the rag and send it for recycling.
Bleed the engine cooling system and check for leaks. Start the engine, warm it up to operating temperature and check the tightness of the cooling system and the liquid level in the expansion tank of the cooling system. The technology for checking the tightness of the cooling system is similar to the engine «M54».