Mercedes-Benz A-Class LWB - Noise from heating/ventilation system

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Sun 2 Mar 2014 17:30
Mercedes-Benz A-Class LWB - Noise from heating/ventilation system - 2dm

A few weeks ago a fault developed suddenly. I pressed the air recirculation button. About 16 loud clunks occur (about 1 per second) then stop. Same repeats each time car is started. Does not seem to affect heating or ventilation. Not sure about recirc, though.

Independent garage seems to know about this kind of fault ('likely motor, about £70') plus up to 7 hours removing and reinstalling the whole dash.

Since it's not causing a problem, might there be a way of stopping the noise - eg remove a fuse, cut a wire etc? Without removing the dash!

Car is 12 yo. Not worth spending £100's.

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Sun 2 Mar 2014 19:12
Mercedes-Benz A-Class LWB - Noise from heating/ventilation system - elekie&a/c doctor

Sound like the recirculation flap gear mechanism is broken.Best and cheapest option is to get the motor disconnected.(one plug).Make sure the flap is set to outside air before pulling the plug.hth

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Sun 2 Mar 2014 22:32
Mercedes-Benz A-Class LWB - Noise from heating/ventilation system - 2dm

How much disassembly is needed do you know to get at that plug?

And how can I be sure that flap is set to outside air? Just by releasing the recirc button?

Help much appreciated; many thanks.

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Wed 5 Mar 2014 14:35
Mercedes-Benz A-Class LWB - Noise from heating/ventilation system - 2dm

Does anyone know answers to my questions above? Would be much appreciated.

rgds

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Wed 5 Mar 2014 15:22
Mercedes-Benz A-Class LWB - Noise from heating/ventilation system - elekie&a/c doctor

The recirc flap motor can be accessed without removal of the dash,but some parts of the underdash trim will need taking off.Remove the pollen filter housing to check that the flap is open to outside air.hth

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Thu 6 Mar 2014 13:45
Mercedes-Benz A-Class LWB - Noise from heating/ventilation system - 2dm

Brill, many thanks.

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