skydon

I have a 2002 C320 and every time you start it, you hear a clicking noise coming from the driver's side footwell. It clicks exactly 8 times and when it does, I feel air blowing out through the vents in the footwell on every click. Does anyone have any ideas on what's going on and what the cost will be to repair it? Thanks in advance for any info!

phattbam

it might be an AC step motor issue. I used to hear that on my '01 c320, ended up replacing all 12 step motors. to my knowledge(may totally be wrong too), step motors control the flow of air for our climate system. therefore the clicking you're hearing are the gears moving but slipping. that was my issue anyways. it's very labor intensive so try to get someone to give you a real estimate on what might be the case.

patrick_y

I have a 2005 C230K SS, it's got about 11k miles on it. Ever since the first day I got it, it's got this small clicking sound (that sounds a tad bit rusty) when you start it up.

I think this is normal (I hope).

Regarding the step motors to the A/C. I've heard there are some funny smells coming out of the A/C. Is this related to the step motor or perhaps something else? Periodically, I get this heavy and somewhat unpleasant smell coming out of my air vents.

phattbam

that may be caused from outside air as well. I dont remember. it's been over 2 years.

FrankW

it is the A/C step motor. I did some cross search on different MBZ forums that's what all the owners end up fixing.

skydon

Thanks for the info. It is the step motor. The repair cost $720.

rpayer

step motor for sure...

you can try to rsync them by holding down the defrost button and recirc button for a few seconds. if the motors just need to be resync'd they should only cycle for about 60 seconds. if the linkage is broken the resync cycle will continue until you turn the car off...head to the stealership.

if your under warranty your good to go. if not it will cost you around 1k. its a known issue.

TruTaing

Ive got this same issue...

Ive found DIY's on how to fix it and have found that stepper motors are no more than like 90 dollars. It mostly involves removing the center console panels to get behind and look at all of the different stepper motors under the dash.

Kind of labor intensive, but i dont think most techs have done this. I think i read somewhere on here that someone brought their car in for this and the techs had NO idea how to take off the center console, so the smart mbworld member showed them how via the thread....

I think I am going to take a stab (if i find time) at taking apart my center console and finding the broken linker arm this weekend. Steve and Wanda said they can probably find the part they just need the exact part number because there are many stepper motors in the car. unfortunately, i dont have a camera to document my attempt.

-j0hn

harpz

To Patrick
Take it to ur dealer, tell them u get a foul smell every now and then (just make sure its not from outside air first!) and they'll fix it free of charge....can't remember what they did but i think they flushed out the system but that fixed my problem...now the only time it smells bad is when the air is bad...