Hi MBworld members,

I just got this C230K about a month ago. I've noticed that the engine (or something in the front of the car) have a very subtle vibration/shaking when I start the car first thing in the morning, or after the car's got sufficient time to cool down to ambient temperature. It only lasts less than a minute and the car runs smoothly after. I was told by the dealer that this engine does that ever since the SLK230K. And there's no problem.

Do your C230K/SLK230K do that? Like I said, it's very subtle...

Thanks

 

Its just the cats warming up. No problem mine does that too, the warmer it is outside the less likely it is that it will do it. Try driving around in your car for a while, then turn it off and let it sit for 5 minutes. Turn it back on and it won't do that.

 

How can a cold catalytic converter cause an engine to idle rough?

Just curious.

 

my bad, i misread the question

 

Yes, I definitely can hear that "Jonh Deere" sound immediately after startup, but it goes away, very abruptly, after about 30-50 seconds. Have no clue what that sound might originate from... My guess was - hydraulic lifters, but they produce a sound of different nature - more like buzzing rather than rumbling... Anyone???

 

It's an air pump, blowing air directly into the exhaust system.
The catalyst will warm much up faster, when there are more oxygen in the mixture, this is one of the ways to get better emmisions.