2002 C230K-"clatter" noise after cold start
 

My 2002 C230K has a "clatter" noise after the car sits overnight. It lasts for 1-2 sec after the engine starts. If the car sits for 2-3 days, tha noise lasts a little bit longer. It does not make this noise if the engine is warm. Dealer said he could not replicate the noise after a stay at the dealership but I don't know how long it sat. I'm guessing timing chain or supercharger related. I'm still in warranty. Thanks.

my first
 

guess would be valve noise. the valve adjusters are hydraulic and under certain circumstances they will bleed down and cause rattling. sometimes a change of oil type will stop it.

tom w

It is the cam advance part. Not sure what it is called, but it has been mentioned on other forums. Since the M111 2.3 engine has Variable Intake Timing this unit makes some noise sometimes. My M271 does some what the same thing. For the first 1-2 seconds after starting I can hear them! It has done it since day one on my 2003. And after 42000 miles it still does it and I have never had any issues.