Ricardo2128

Hi Guys, i am super excited to have joined this group of dedicated individuals who are passionate and committed to taking complete care ownership of their cars.
I have a 2004 W203 M271 C180k, had it since new and it has not missed a beat. Now i am replacing some wear like, tensioner pulley, idler pulley due to noise. The main reason is the diesel sound my petrol engine is emitting.
I mean this thing is so bloody loud and embarrassing. After stripping the necessities i have diagnosed the A/C Pulley has a lot of give between turns ( as i turn the pulley forward and back slightly the noise is evident.

My question here is can i just replace the A/C pulley?

alecmascot

The usual reason for a noise like that is the failure of the alternator pulley clutch.
Check that it is free in one direction and locked in the other.

jkowtko

To answer your question specifically, yes should you be able to replace just the pulley/bearing assembly ... I see those offered as MB Genuine and aftermarket. I even think you can replace just the bearing, although it looks like it may require more "surgical" work to remove and replace the bearaing on the pulley wheel. However this is only relevant if your pulley is wobbly indicating the bearing has play in it. Otherwise I would look to alecmascot's suggestion ...

Ricardo2128

Thank you so much. After looking to replace the Compressor unit, the cost from a local MB dealer in Sydney is $1800. The cost for the clutch and pulley is $500. These guys are out of control! The cost of a new compressor from Denso is $900, now I am determined to just replace the clutch to be safe and pulley.

The other cause of anxiety in this DIY scenario, the full commitment it will take to remove the entire compressor. For a pro 3 hrs for me maybe 2 days. Reason for removing the entire unit is not enough room in the front to access the pulley with a wheel removal clamp.

jkowtko

Note, if you have the Denso 471-1580 compressor like they do here on the M271, then there is no external clutch ... that front plate just has some rubber bumpers on it that fit into the holes in the pulley ... I believe the "clutch" on this unit is internal. The only thing you can replace on this unit externally is the front plate with the bumpers, or the pulley/bearing.

Ricardo2128

Thank you jkowtko for your help. I will need to verify if indeed this is the correct unit for my VIN. I have indeed checked the pulley on my u it and I can confirm the DIESEL noise emanating from the car is the pulley. The unit you mentioned though seems to have an external clutch though. Again I will need to verify and study the front attachment ahead of the pulley itself but It does look like the clutch engagement.

jkowtko

Here is mine: ... you'll have to figure out if you have this unit or one with the external clutch.

02C240

1st Lite,

Did you just open the receiver/drier to replace the drier cartridge or did you replace the whole the whole unit? It seems difficult to open the nut on the reciiver/dryer even with the special tool (external hex socket)...

BTW I have the oily belt issue you had for the last two years. I also narrowed it down to leaky compressor front seal.

1st lite

02C240,
I opened the receiver/drier unit and replace only the cartridge. I thought I might round off the internal hex fitting, but managed loosen it. You might want to spray some penetrating fluid and attempt to loosen after a day or so.
Yeah. I could never figure out where that light film of oil was coming from until one night I heard something kinda lightly snap somewhere in the engine compartment. That's when my HVAC went kind of weird. No cold air and the system could not get rid of condensation inside the car when it rained. Replaced the AC compressor and all the recommended parts when doing this job. Everything is still functioning 100%!
Good luck with your AC repair.

02C240

Great to hear. I will spray some PB before I attempt removing the nut. Thanks.