W203 Stepper motor

[Theothers]

Hi all yet another 2001 car with a problem, this time its a stepper motor clicking, does anyone know of someone in kent that would be able to change it? I have looked at oyther posts and it seems that Steve the Mechanic might be the man, but I don't know how to get hold of him.

Thanks for any help.

 

[BlackC55]

Its roughly an 11 hour job to do depending on what motor is clicking. I would be happy to help just PM me. I have done quite a few to date.

 

[Theothers]

Thanks for the offer but I am in Kent so probably a bit far. I have been quoted £ 500 plus VAT which is OK but it just seems a bit mad to fix a little click. Is it possible to turn the motor off in the star system then the click will just go away, OK i accept that the passenger will get cold feet, but I guess she can put thick socks on

 

[Rumble]

Heres a write up and picture guide if you feel like tackling it yourself, apparently its usually the linkage rather than the stepper motor that fails (piece of plastic that snaps) but you might want to get both just in case.

http://www.mbworld.org/forums/showthread.php?t=177068&highlight=stepper+motor

Btw have you tried resyncing your ac system ie holding down the windshiel defrost and recirculate buttons down simultaneously until the lights start flashing alternatively!?

 

[1998K]

Which W203 year is mainly affected?

Mine in a january 2003 C270 W203 car!

thanks a lot

 

[Theothers]

Heres a write up and picture guide if you feel like tackling it yourself, apparently its usually the linkage rather than the stepper motor that fails (piece of plastic that snaps) but you might want to get both just in case.

http://www.mbworld.org/forums/showthread.php?t=177068&highlight=stepper+motor

Btw have you tried resyncing your ac system ie holding down the windshiel defrost and recirculate buttons down simultaneously until the lights start flashing alternatively!?

Hi thanks for that I will have a look. I have tried the resnc but am not sure if I did it correctly. I held down the buttons and the lights flashed alternately and the vents go through a cycle but it doesn't stop until I restart the car, should the ressnc stop?

Thanks for your help

 

[Theothers]

Which W203 year is mainly affected?

Mine in a january 2003 C270 W203 car!

thanks a lot

I think its mainly the 2001 cars but as far as I know its any pre facelift W203

 

[1998K]

thanks a lot for the info!

 

[miro]

90% chance it is the footwell flaps. They are located behind the radio and with some careful handling it can be done through that opening. The first time I did it the job took me about 2 hours and that was really just learning.

The past cost about 5 Euro and if that is your problem then do both sides. Anyone with just the right small tools can do it. You will need a 90 degree ratchet and a T20 bit. Mine is japanese and it fits in the small spaces.

To remove the motor you need to undo 3 screws. It will lift out and then you replace the plastic arm that is pushed on (probably cracked). The longest part of the job will be threading the lever back onto the slit in the heater box. The lever moves across like a windscreen wiper arm engaging the flap through a slit in the arm. The torsional strain is quite low which is why the failure of the plastic lever is surprising. Shown below is the weaker version replaced before it had a chance to annoy me. The newer version has more plastic.

If it is the fresh air flap or the carbon filter flap then its a little more serious. As stated above. Best is to get a reading of the fault.

 

[Theothers]

90% chance it is the footwell flaps. They are located behind the radio and with some careful handling it can be done through that opening. The first time I did it the job took me about 2 hours and that was really just learning.

The past cost about 5 Euro and if that is your problem then do both sides. Anyone with just the right small tools can do it. You will need a 90 degree ratchet and a T20 bit. Mine is japanese and it fits in the small spaces.

To remove the motor you need to undo 3 screws. It will lift out and then you replace the plastic arm that is pushed on (probably cracked). The longest part of the job will be threading the lever back onto the slit in the heater box.

If it is the fresh air flap or the carbon filter flap then its a little more serious. As stated above.

Best is to get a reading of the fault. If it is a footwell flap then make some lame excuse to leave the dealer and the forum will help you.

Thanks for that I it can be done through the radio opening I wounder why people take the whole dash apart?

 

[miro]

Thanks for that I it can be done through the radio opening I wounder why people take the whole dash apart?

I dont speak for other people.

 

[jaymanek]

dont quote me on this but in the Merc Enthusiast W203 in depth review, they said that a lot of owners just snap off the part that causes the clicking and it really has no detrimental effect...

 

[miro]

dont quote me on this but in the Merc Enthusiast W203 in depth review, they said that a lot of owners just snap off the part that causes the clicking and it really has no detrimental effect...

Sounds like a load of nonsense. To snap off the annoying part would be just as much effort as replacing it. Most of these cogs are impossible to reach whilst the car is intact.

Just another urban myth written by someone who doesnt actually fix cars.

 

[BlackC55]

Thanks for that I it can be done through the radio opening I wounder why people take the whole dash apart?

Because its two different faults at different motors.

 

[jaymanek]

Sounds like a load of nonsense. To snap off the annoying part would be just as much effort as replacing it. Most of these cogs are impossible to reach whilst the car is intact.

Just another urban myth written by someone who doesnt actually fix cars.

yeh i thought so, im going to find the article later as im now intrigued as to the exact wording..

 

[BlackC55]

yeh i thought so, im going to find the article later as im now intrigued as to the exact wording..

It is possible to do this but it is not the correct repair.

 

[Rumble]

Hi thanks for that I will have a look. I have tried the resnc but am not sure if I did it correctly. I held down the buttons and the lights flashed alternately and the vents go through a cycle but it doesn't stop until I restart the car, should the ressnc stop?

Thanks for your help

Yes the resync should stop on its own, although if it doesn't stop switch off the car and restart and try it again just to make sure, doesn't hurt.

im sure it'll be the broken plastic if you can replace it through the central console then that'll shave a good few hours off the repair time.

 

[CMR]

Hi, sorry to butt in, this thread has started quite advanced with - 'this time its a stepper motor clicking', and has carried on advanced (for me anyway!). I have clicking noise too from passenger side (engine compartment). Can someone point me in the right direction to find out more about this please? A quick search reveals something about noisy purge valves too. I'm getting a bit lost in all this!

 

[miro]

Hi, sorry to butt in, this thread has started quite advanced with - 'this time its a stepper motor clicking', and has carried on advanced (for me anyway!). I have clicking noise too from passenger side (engine compartment). Can someone point me in the right direction to find out more about this please? A quick search reveals something about noisy purge valves too. I'm getting a bit lost in all this!

How do you know it is from the engine compartment. Usually something from the engine area has a rubbing sound or a thump every time the tyres rotate (like the parking brake cable rubbing on the drive shaft).

The click in the heater box trick is 3-5 clicks when you start your car and then it gives up.

 

[Rumble]

As Miro said they are distinct clicks and stop after a while, also if you do the resync (press and hold the defrost and recirculate buttons until the lights flash) the system will switch between motors, the broken motor(s)/link(s) will be evident by the clicking pattern first heard when you started the car. The resync process will not stop on its own if there are any faulty motors or links without turning off the engine, if there are no broken parts the resync process will stop on itself.