knocking noise from the dashboard
 

Hi All,

Please help.

Since last week when I switch the car on (CLK 320 2004) for the first time each day, there is a knocking/clicking noise that comes from thedashboard. After a few minutes the noise disappears.

I have tried turning off thestereo in case it was coming from the speakers. I have tried turning off the heater.

Has anyone had the same problem or know what could be wrong??

Thanks

RE: knocking noise from the dashboard
 

Hi, I own an A140 and Just today Ive noticed a similar sound from behind my dashboard.

Im my case by Turning the fans onto Full there is a noticeable fluctuation in blower power as the knocking noise contuinues.

the noise stops after approx 30 seconda and the fans function normally.

Im looking at other forums and i am suspecting a servo motor that controls the vents.
However I havent found anything definitive yet. If I do I will let u know.

Have you seen this fault description
http://www.benzworld.org/forums/w203...oise+dashboard

and does it sound like your problem ?

RE: knocking noise from the dashboard
 

For some reason I thought I wrote on this thread already guess it was else where. Anyway sound's like a broken footwell flap arm. I've seen several of these in c's but they use the same climate control system. There is a small motor that moves an arm to open the footwell flap. This crackes in the socket and the motor just turns in the plastic arm causing the clicking sound. You notice this upon start up becausethe climate control mod is doing a self check. It then will see that the motor is just spinning and will shut that one offfrom operation. You may notice you have no drivers footwell air. real bear to get to.

RE: knocking noise from the dashboard
 

Thanks tmb... I brought it to my favourite mechanic tonight and after some investigation with a torch inthe footwells of the car he reported that he could indeed see some broken cogs in the heater matrix. a couple of hours ripping apart the plastic manifolds and a few generic parts (im told) should fix the problem.

Happy motoring all...
Mush

Could this fault also manifest itself with no air to the passanger footwell i think i have the same problem load clunking / flap noise coming from behind the dash on start up for a couple of time i also here a difference in air pressur as the noise occurs. I have no air making its way to the passanger foot well. !!