05 E320 Cdi annoying idle vibration
 

Hi Folks,

I'm the 'new' owner of a 2005 E320 cdi with only 81k on the clock, the car had some things wrong with it when I bought it and I've been going through and fixing them, so far I've done:

air filter
oil and oil filter change
diff oil change
new engine mounts
new transmission mount
new thermostat


The problem I'm having right now is the engine has a bad vibration at idle, in drive, park or neutral it makes no difference, it has all new mounts so I don't think its that. I took it to the local mercedes benz dealership here (before I did the transmission mount) and they told me it was the trans mount that was shot and was causing it.
However after putting a new mount on the vibration is still there.

It also has quite a big kick, when I switch the engine off.

I did some googling and the best explanation is either the alternator pulley is bad (it has some kind of damper or clutch in it?) or one of the fuel injectors is bad and at idle is injecting just the wrong amount of fuel, causing the vibration.
It does need a new serpentine belt, so I'll get that done and check the alternator pulley when I change it.

Can anyone help? If I knew the benz dealer could fix it I would take it back, but they seemed more interested in billing me for other things and washing my car than actually fixing the thing I brought it in for.

Thanks

Chris