SilverBulletAMG

Has anyone had their "stepper motor" go out? Dealership tells me mine bit the dust and it's a $3k repair. Jury is out on whether or not warranty will cover it.
Symptoms are loud and obvious. It makes a very loud and rapid ticking noise like an igniter for a BBQ in stereo. The sound comes from the passenger dash area. I'm told it is some sensor that works with the charcoal filter and the sensor is supposed to scan to the left and then scan to the right and stop. My sensor gets stuck on one side and keeps tapping for a good minute or two every time the car is started up.
The dealership also said it would be a 5 hr job (probably 30 minutes realistically) just to get up under the dash and unplug it. I personally could care less about some charcoal filter sensor thing but it cost just as much to unplug it as it does to replace almost. Hopefully warranty will cover this one....

ScottW911

I have no idea what your tech is telling you about some sort of charcoal filter scanner, but when my stepper motor went out, I learned that it is the motor/arm that changes the direction of the airflow through your HVAC system. The motor does not actually break (most of the time). It is actually the cheap plastic arm that connects the motor to the flap. The sound you hear (I described it as someone flicking a huge rubber band at the underside of my dashboard) is the motor attempting to make the changes. I believe it gives up after a few minutes.

On the repair front, mine was covered by CPO but they did include the pricing on my worksheet. The total for the part is only about $60. The downside is the entire dash does need to come out of the car. It will be billed at about 5 hours. My total came to $607. There is a DIY thread on this, right here in this forum too.

Do not let them charge you or your insurance company $3k. Total rip-off.

///AMG4EVER

It's not the stepper motor (or the sensor) per se, it's the plastic flappers/arms that breaks. Unfortunately, the stealership is right. It is not a 30 minutes job. It's an easy 3 hours job even with 2 people working on the car with the right tools. The complete dashboard has to come out. If I remember correctly, we have 4 (or maybe) 6 of these motors across the dashboard. It is highly recommended you change all the flappers at once with the updated design.

This is a very common problem of the W203s. There are instructions on the W203 C Class forum. Do a search under "stepper motor" or "clicking noise".

Edit: Ok, Scott beat me to it, but it's the same thing. The actual part, a pair of plastic arms, is around $8-$10 plus labor which you can account for as 3-5 hours.

SilverBulletAMG

Interesting. Thanks for the info guys. I will print your reply and take that in with me. As I had mentioned in a previous post, the manager is great. His workers, not so much.
Keep the testimonials coming. It's good ammo to bring with me.

TemjinX2

yeah i had the same problem for the last 5months. SInce it doesn't really effect my heating or cooling..i've just been ignoring. I guess when i get reallly really bored i might take out the dash.

But even spending $600 on this doesn't really seem like its worth it.

i'd rather take that $600 and spend in on tuning.

SilverBulletAMG

I couldn't live with the sound. Even though it only does it at start up, it still drives me nuts. Not to mention when others are in the car and it makes that noise, people go WTF....

TemjinX2

just turn on the radio...and tell the people in your car its your supercharger starting up...lol..

Eleventeen

+1 on the flapper arm. Set of two cost me about $9.00 and I did it in about an hour without removing the dash, but it takes a little creativity and probably won't work if you have hands like a 6'5" lumberjack.

Here's what will really tick you off: Mercedes has redesigned them and made them thicker because they know the originals suck. Just like the radiator, A.I.R. pump relay, crank dampener/pulley, front "upper" control arm bushings, and every other piece of crap part they built these cars with. By redesigning these parts, they basically admit the originals sucked, but still have the stones to charge you to fix it several years later.

c32used

+1

SilverBulletAMG

That's a good point. My control arm bushing still isn't fixed. Last time it was in the shot I tried to get it repaired under warranty and the warranty folks said no-go because it was an "update part" which they conveniently don't cover. However, there is a new manager in the shop and I trust he can be more convincing and hopefully get them both replaced.