Loud clicking behind dash - climate control?

[grayb]

I mentioned this problem in a similar post in the General Discussion forum, but it obviously belongs in this section.

Our W209 CLK 2003 has a loud rhythmic click/knock from deep behind the dash on the passenger side that occurs when the ignition is turned on or soon after starting the car. The noise lasts for a minute or two. It sounds like a solenoid or valve shutting/opening.

We asked the dealer who supplied the car - he had heard the noise and had the indie Merc garage who had just serviced it check it out. They said that no fault codes came up on the computer and that they didn't know what it was, though it seemed to be related to the climate control system. They pointed out that it doesn't happen if the Activated Filter button is on.

This doesn't sound right to me, so any suggestions? We would like to get it diagnosed so that any warranty issues can be sorted withing the warranty period.

 

[Ellsy Tanners]

Hello,

Your control flap for the active charcoal filter, has broken and stripped the gear on the stepper motor. This is located on the heater box at the back on the passenger side.

The bad news is that the whole dash has to be removed, together with the centre console and the metal frame behind the dash have to come out. Then the heater box must be pulled forward and the stepper motor and broken gear can be replaced. If the flap is stiff then the charcoal filter section of the heater box must be replaced as well, as it will just shear the gears again in a few months.

This is about 8 hour work so it wont be cheap unfortunatly.

This is very common on all 203 and 209 with charcoal filters, so i am amazed the two garages dont know what was wrong!!


Sorry to be the bearer of bad news.

 

[grayb]

Thanks for such a quick reply, Ellsy. Not good news, agreed, but the dealers own warranty (not insurance type) should cover this, I think.

I have checked with our local M-B dealer and he agreed with your diagnoses on the face of it, and reckoned a 4 figure repair cost with them.

Just shows how useful forums are!

 

[Ellsy Tanners]

I hope you get this sorted, its not a bad job to do, but very time consuming, a good days work and thats not hanging around.

Try and get them to replace the damaged section of heater box at the same time as its warranty.

Good thing you have a warranty.

 

[grayb]

Spoke with dealer this morning - he was anxious to do the right thing and apologetic. Car will be booked in with a Merc specialist indie garage week after next. We will certainly make a point of asking for the damaged section to be replaced as you suggest - thanks again for your advice!
I must say this dealer (a prestige car specialist) seems like a good guy to do business with. Nice after we got our fingers burned buying the C43 privately (the a/c compressor was u/s when we bought it).

 

[CMR]

... If the flap is stiff then the charcoal filter section of the heater box must be replaced as well, as it will just shear the gears again in a few months...

Does this mean that there is a permanent fix to this problem?

I have same problem but was advised I could get it fixed (8-10hr repair) and then find it may go again at some point! or just live with it - which I'm doing now. I think there a lots of people that live with it on the basis it may happen again? the ones with warranty obviously get it fixed.

 

[Ellsy Tanners]

Does this mean that there is a permanent fix to this problem?

I have same problem but was advised I could get it fixed (8-10hr repair) and then find it may go again at some point! or just live with it - which I'm doing now. I think there a lots of people that live with it on the basis it may happen again? the ones with warranty obviously get it fixed.

Yes if you replace the section of heater box with the charcoal flap in, then it should be a permanent fix. I have never had a reocurance when the flap has been replaced.

 

[bootneckbandy]

Clicking Behind Dash

I ad a similar problem with my 203 C Class, after searching the forum it looked like the air vent motors.
I contacted Canterbury maim dealer and they confirmed that the car would need to have its dash removed, 6 - 8 hours just to check the fault, that's alright I have a warrenty! After contacting the warrenty company I was informed that the warrenty doesn't cover this fault. One has to ask what is the point of such a warrenty on used cars, especially after I had only owned the car for 3 months. I then contacted Caterham "Mercedes Direct" they were first class, the car went in whilst I was on holiday and the fault was repaired free of charge. Apparently there is a plastic cog with a star shaped spindle in the middle, the cog had split and the spindle was spinning on start up making the clicking noise.
I was told a repair would be in the region of £800 for such a small part.

Thank you again Caterham.

 

[grayb]

Yes if you replace the section of heater box with the charcoal flap in, then it should be a permanent fix. I have never had a reocurance when the flap has been replaced.

Ellsy's words have come back to haunt us. Seems the warranty repair might not have included the heater box section - as the clicking has returned, one year on...

Anyone know how long it would to do this job? Is it within the compass of a reasonably comptetant general garage? If there are any links to part numbers or instructions they would be much appreciated.

And yes I did ask them to replace the flap as well as the broken gears. Learning point - dont trust vague assurances from a car dealer!

 

[Alex Crow]

Ellsy's words have come back to haunt us. Seems the warranty repair might not have included the heater box section - as the clicking has returned, one year on...

Anyone know how long it would to do this job? Is it within the compass of a reasonably comptetant general garage? If there are any links to part numbers or instructions they would be much appreciated.

And yes I did ask them to replace the flap as well as the broken gears. Learning point - dont trust vague assurances from a car dealer!

well i am sure that is a job for a competent indie, we would be very happy to do it for MB repair times, but at a significantly discounted labour rate. sadly we are in suffolk, a fair trek from kent, but if you want any advice or a firm quote ring me at work tommorow - pm or e-mail me for contact info.

many thanks.

 

[goodpw]

Bugger !!

Hi All.
2003 CLK500 Avantgarde (R/Hand drive)
Usual story about clicking/knocking on start up.
Right, just had all the lower dash /centre console out to check the levers, all were OK. so I did a temp re-install of the control panel to fire it back up.
The noise is still there & coming from above the fan & filter assembly right up in the top left hand of the dash.

The visible gear set between the fan & filter looks OK.
(M2/5 Fresh air/recirculated air flap positioning motor on the site shown below)

so I think it's the one right at the top.
(A32m2 Activated charcoal filter flap adjustment motor on the site shown below)

I've run out of time for now so will put it all back togethe & attack the whole lot next year. It is a PITA of a job just to get the lower dash & console out with plenty of hidden screws (the one under the light switch hidden up thru the brake release pull had me for ages)

My advise....live with it.

I did however find this site.

http://bayhas.com/mercedes/c209/contents/climatecontrol/climatecontrol_ventsys.htm

regards. Phil.

 

[Scrottocks]

Could it be a very small lady Flamenco dancer with castanets?

Arthur

 

[goodpw]

If only. I'm great at repelling woman so would be easy to get rid of.

 

[Alex Crow]

.................so I think it's the one right at the top.
(A32m2 Activated charcoal filter flap adjustment motor on the site shown below)...............

That will be the one, and a dash out job to even get near it.

 

[goodpw]

Scale wise how far away was I.

This is how far I got
Centre console & comand/heater control carriage, Glove box, Steering wheel surround/apron & Speedo console all out essentially everything below the upper dashboard was either out or dangling (CD changer in glovebox didn't want to be evicted).

How much more work is it to get the upper dash board off, on a scale of 1 > 10 what number was I on.
regards.
Phil.

 

[Alex Crow]

Number 6 my man, not far away.

 

[PierreK123]

Hi all,

In the light of this problem re-occurring and the cost involved and all that.
I was wondering if it is at all possible to by-pass or disable the stepper motor either by simply removing it or the power to it or even from the fuse box (if it can be isolated)
What would the result be?
Maybe just a permanent fault message on the dash? Sure better than the clicking...

I'm aware that this will influence the climate control but I'm wondering to what extend will the impact be worse with a flap/stepper motor malfunctioning, compare to being disabled since there are other air vents so it's not like you will overheat or freeze to death

Anyone ever disabled it before or know where the relay is that controls it?

Thanks

 

[alexanderfoti]

Best to start a new thread rather than bump a 6 year old one!

The stepper can be unplugged and will leave no warnings on the dash. It is controlled directly from the climate controller.

 

[PierreK123]

I see your point on bumping a 6 year old thread but to me starting a new one is worse since the info is still the same so why not just have everything together. One of the terms of most forums are always something like: "Read this before you post" and then it tells you to search for possible answers before posting. So it contradicts the effort to reduce duplication on the same idea. I would much rather have one post dealing the the same issue that having to read through tons and then try and combine all the answers. There you have it - my 2cents on the matter. I'll start a new thread now since you are the Moderator and might just get irritated with my responds and ban me

 

[alexanderfoti]

I see your point on bumping a 6 year old thread but to me starting a new one is worse since the info is still the same so why not just have everything together. One of the terms of most forums are always something like: "Read this before you post" and then it tells you to search for possible answers before posting. So it contradicts the effort to reduce duplication on the same idea. I would much rather have one post dealing the the same issue that having to read through tons and then try and combine all the answers. There you have it - my 2cents on the matter. I'll start a new thread now since you are the Moderator and might just get irritated with my responds and ban me

Don't worry, we aren't like that here

There is lots of stuff on this thread that isnt that relative, and as its a common problem that we all know about, we will likely end up with a new thread that is more accurate.