My 09' C300 Sport had a whining sound around 1000-3000rpm and above that the exhaust covered it, but I figured the belt might have got a bit stiffer from the drop in temperature. I examined the belt myself when the noise started and everything looked and ran normal. I did a multi-point inspection Mar17 and the Tail Lights recall Oct01 and the Mercedes Techs didn't mention anything.
I got on the hwy after leaving the car wash and heard weird ticking sounds similar to sand hitting the car under body. Eventually lost power steering, power, the whole deal but still managed to limp the car another 5km home. Popped the hood and rubber was every where, the idler pulley was jammed and the belt came off from there. I assume the ceased idler pulley was hot and cold water shatter the plastic guide/guard which shredded the belt. I'm going to replace the idler pulley and belt, hopefully nothing else was damaged. I'm loosing faith in Mercedes, bought the car at 67,000km and the tail lights burnt out, blower motor shorted last winter, Engine light for Thermostat P0128 illuminated, now the belt. In my research I also found out the 272 engines have a balance shaft problem that will cost $6.5k to fix.

Anyone knows the scope of damage from the Poly V Belt coming off? Also if you have a schematic diagram of the Belt to guide me installing it.

this happened to me also. Your plastic idler pulls feel apart. This is a common issue. It's a 5 min job to replace the pulpy and it cost about $15.00. You will need a new belt also.

My idler pulley bearing seized and caused damage to the belt. The Alternator light come on and squealing noise from belt. replaced belt and idler pulley no more problems

Same car , same problem at 70,000 miles .Mechanic wanted to replace this and that .. I told him to replace only the belt ... 5000 miles later no further problems .

Look here

http://www.benzworld.org/forums/w204...tensioner.html

Sorry to hear that but the issues you've had with your Benz is quite minor. I had to replace my thermostat but it was an easy DIY job. The belt failure is dangerous but doesn't reflect on the reliability of the car. Mine also had a jerky shifting transmission but having the tranny flushed and refilled with a new filter and seals took care of the problem and shifts smoothly now.

well for one, its not a v belt, and for 2, your socks and flip flops look needs a lot of work.

I don't think your M272 have a shaft balance problem. Yours is 2009 model year. Balance shaft problem is usually found in most 2006 and some 2007 model years. Your M272 engine should be fine.

Now now be nice

Thanks for the help guys. I replaced the idle pulley and Drive belt ($150 OEM). Everything works normal. But I think I might have broken the seal slightly on the Tensioner, there is a slow oil leak whenever the strut moves. Not critical yet though.

Do these pullies share relations with the c63 09' cause mine just shredded also and found the rest of the pully at the bottom guard

Not sure about the AMG but all 4 of my last cars took the same one. I keep one on hand in the garage.

I'll have to check my friend's 2010 C63 and get back to you