A/C - Humming/Howling Noise With heater ON
SI B 64 19 05Heating and Air Conditioning
January 2006
Technical Service
SUBJECT
Humming/Howling Noise when Heater is Used
MODEL
E60 (5 Series) all except N52
SITUATION
The customer states that when the heater is used there is a humming/howling noise coming from the engine compartment. The noise occurs when the heating/air conditioning is set to automatic mode.
CAUSE
Support for the auxiliary water pump.
PROCEDURE
1. Verify that the noise is currently present and unplug the electrical connector from the auxiliary water pump.
2. If the noise is gone then continue with the procedure outlined in this service information. If the noise is not from the auxiliary water pump, continue standard troubleshooting.
3. Check the coolant to make sure it is at the proper level.
4. Check the auxiliary water pump and hoses to ensure that they are not hitting the body.
5. Replace the auxiliary water pump fastening clamp with an improved part.
PARTS INFORMATION
WARRANTY INFORMATION
Covered under the terms of the BMW New Vehicle Limited Warranty.
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