Hello,

After spending some time researching the matter online I decided it would be best to post the problem on this forum. I own a 2011 A180 Bluefficiency with 19000 miles. It is a fun car to drive also drives comfortly like much bigger cars, has loads of space but has been somewhat unreliable. During the two years of warranty I allready had to replace the starter, discs and pads on rear wheels(after only 6500 miles) a reverse light switch and some other minor things.

All in all it was a pleasant expirience until 4 months ago when the car developed at first quiet chirping noise which slowly got louder and louder. The noise is of constant frequency, not changing with engine revs and sometimes goes away and then comes back without any kind of pattern. I would say that it's louder when the engine is colder but not significantly and it doesn't always go away when the engine warms up. Due to the fact that the noise is not always present it took me quite a few trips to my mercedes repair shop before the staff there could hear it since the first two visits the noise was not even there and everyone thought I was crazy. After being repeteadly told that everything is okay and normal I gave up and went home. After two days the noise came back and this time I went straight to the repair shop, left the engine running while I took care of the necessary paperwork so that the mechanic finally came to my car and heard the noise himself. The conclusion was without a doubt that one of the belts went wrong, based on the non changing frequency they replaced my alternator belt, I paid the bill and went home happy that the problem is finally resolved.

After just one day the devilish sound came back, and this time I was absolutely furious, went straight to the repair shop and told them not to bother calling until they locate the problem. They caled me the same day, saying that the camshaft's pulley(they told me that the rubber on it has worn out) has gone bad and is turning excentrically, as a result, the chain is running a bit loose. They also mentioned that they have never seen this kind of failure on a car with such low mileage before and would contact Daimler factory for some discount approval or maybe even free out of warranty repair. I felt perplexed by the situation since I knew that chain related problems were not suppose to happen until 100k miles or so, but was also somewhat happy because I had faith in Daimler approving my free repair.

A few days later the call came in from the repair shop, explaining that Daimler refused any kind of discount and that the repair itself is going to cost me 500+ euros. So I am turning to you people before I pay for yet another repair with potentialy wrong diagnose and hopefully avoid replacing 5 unnecessary parts before they actually manage to find out the true cause of the problem. I am attaching the youtube link for the noise video:

http://www.youtube.com/watch?v=-P3OH...ature=youtu.be

P.S. Sorry for the excrutiatingly long post, I am not very good at getting to the point