Dima_Khanjala

Hey guys,

I purchased 2014 C250 a few months ago. While it was winter I wasn't using AC, but as it got warm the problem started. I'm experiencing strong metal-to-metal vibration on my steering wheel as well as the whole car body. For example, it feels like some metal details friction each other right behind my steering wheel or under my feet. It happens as soon as I hit the AC button and AC compressor starts working. Firstly I decided to change engine mounts and transmission mount. Although OEM engine and transmission mounts turned out to be in good condition, I still changed them and installed brand new ones. NO RESULT. I don't think it might be AC compressor itself because AC works just fine, freezes very quickly and strong. Can you guys guess what might be a problem? Because I'm getting mad. The engine itself is in very good condition, checked by experienced mechanics.

xsever

Do a visual inspection of the AC compressor when it comes on. Is it vibrating? Is its pulley vibrating? Is the idler pulley vibrating? The AC coming on adds tension to the belt so all the pulleys connect to it will feel a "load". Maybe one or more need replacement. Start from there and let us know what you find out.

Dima_Khanjala

The AC compressor itself doesn't feel to have any excess vibration, its pulley spins smoothly too. I also replace idler pulley and drive belt, but nothing changed. I think about changing belt tensioner although it works just fine.

NZ-Merc

Hi,
Have you checked incase the fan belt is incorrect length.
Is the idler pulley stable when a/c is on and off or does it flap about, did you see the answer in the other thread you asked a question.

Dima_Khanjala

Drive belt spins perfect on every pulley. I also replaced idle pulley, it's nice and spins firmly. I unfortunately didn't get an idea what might be wrong.