# 2007 BMW Z4 ( Over Heating Problem)



## Gregstil7 (Jan 7, 2021)

Good Day ,Have aZ4 3.0 with a over heating problem Have changed out electrical Water pump all hoses thermostat ,And alternator, radiator coolant is circulating,If I put the car on a load it's overheats .and the heater not working ?


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## Doug Huffman (Apr 25, 2015)

All BMW are now recommended to vacuum fill. A dry electronic water pump is likely stuck corroded frozen and ruined. The journal bearings are exotic graphite filled epoxy Graphitar® that must always be wet with proper anti corrosion solution. The Brush-Less DC - BLDC motor cannot normally provide torque for breakaway, so there is a routine in ISTA. Best wishes.

Also

Attention!
Risk of damage:
Non-visible damage to the coolant pump.
Forcibly removing, installing or dropping the coolant pump down will damage it. 
Remove and install the coolant pump without damaging it and without applying external force.
Avoid impacts/knocks to the coolant pump (e.g.. by tools, falling down, hard contact with base).
Necessarily renew the coolant pump after it falls or receives hard blows.


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