BMW E90 Thermostat Replacement – 2007-2013 3 Series – N52/N54/N55

BMW E90 Thermostat Replacement Checklist

• Plug the electrical connector back into the thermostat.
• Connect the cylinder head coolant hose back on to the thermostat and tighten its hose clamp.
• Rotate the thermostat back into the engine.
• Install the two thermostat mounting bolts and torque them to 6 Nm (4.5 ft-lb).
• Reinstall the water pump hose on the rear of the thermostat and tighten its hose clamp.
• Close the locking clip on the heater return hose and push it onto the thermostat until your hear it click into place.
• Close the locking clip on the lower radiator hose and install it back onto the thermostat. Make sure you hear it click into place.
• Install the heater return line back onto the frame of the vehicle using the two T30 mounting screws.
• Install the cooling fan back into the front of the vehicle.
• Reinstall the cooling fan plug.
• Close the locking clip on the expansion tank vent hose and install it back on the expansion tank.
• Reinstall the intake duct.
• Reinstall the transmission cooler onto the back of the cooling fan.
• ***If you are working on a turbocharged engine, reinstall the intercooler. MAKE SURE you hear the charge pipes click into place on the intercooler..loose charge pipes will cause a rough idle and check engine light.
• Reinstall the front belly pan.
• Refill and bleed the coolant system (see Section 4 below).