Water Pump
Water Pump
Section titled “Water Pump”The M54 water pump is mechanical (belt-driven) with a plastic impeller. The plastic impeller is the weak point — it can crack or shed blades, causing loss of coolant circulation and overheating.
Symptoms of Failure
Section titled “Symptoms of Failure”- Coolant leak from weep hole
- Overheating at idle or highway speeds
- Squealing or grinding noise
- Temperature fluctuation
Replacement
Section titled “Replacement”Part: 11 53 1 437 040. Recommended upgrade: Stewart water pump (metal impeller).
Installation Notes
Section titled “Installation Notes”- Replace with cooling system overhaul
- Water pump bolts: 10 Nm (M6 into aluminum)
- Always replace O-ring seal
- Bleed cooling system after installation