ML320Air con makes clicking noise (air blender? Step motor?)

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Joined: Sun 13 Nov, 2016 5:38 pm
Model you own: w163

ML320Air con makes clicking noise (air blender? Step motor?)

Post by Spooky817 » Sun 13 Nov, 2016 6:25 pm

Hi guys,

we've had this beautiful ML320 for a little while and bought it because initially it looked like one of the better ones available at the time with not too many of the known issues they tend to be able to develop and it had only 126t km's.

Anyway, it didn't take long to delop this annoying issue, when the centre dial for hot / cold, when on cold / blue, there is a loud audible ticking noise, about one tick per second. I've taken the glove box out and can see the arm that makes the ticking noise when in the position where the arm is furthest towards the front of the car, looking through the glove box opening.

I've removed the glove box and can see where it is coming from. However I am now not sure how to repair it. Is the Air blender motor? The one on the left? And is making the clicking noise? Or is it the stepper motor? Are they the same thing? Does it need replacing? If so, does the dash need to be removed to replace the motor? I have read elsewhere that it gets stuck and be unstuck or some sort of tapping on the motor could solve the problem. But not sure how to do either. Any help much appreciated. Video and photo are below.

Thank you!


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300 SLR
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Joined: Fri 10 Oct, 2008 12:10 am
Model you own: w111
Location: Perth WA

Re: ML320Air con makes clicking noise (air blender? Step mot

Post by Bartman4800 » Mon 14 Nov, 2016 3:47 pm

I think the clicking noises come from the plastic gearbox that transfers the motor rotation to the quarter turn movement you need for the flap.

Most likely a non serviceable item i.e. replacement only.

My 2001 VW passat is full of them and some stopped working...

1963 220 Sb Sedan "Kermit" (Australian Assembly)
1960 220 Sb Sedan "Zum Schlachten" (Early German Assembly, with a torsion bar spring for the bonnet) - Stored in Country WA
1981 Subaru Brumby 1.8 with Weber and 5-speed box "little utie" - Sold to another enthusiast!
2006 Ford Focus "daily driver"
2002 VW Passat V6 30V Station Wagon (SOLD - This car into a money pit)
2011 Kia Sportage "Missus commuter Bus"
2002 Mitsubishi Rosa Bus (converting it to a motor home)

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