The camshaft adjuster solenoid (which is related to the variable valve timing system) may fail or timing chain/balance shaft components may wear, resulting in illumination of the Check Engine Light and various drivability issues. Mercedes-Benz has released a service bulletin outlining specific repair instructions depending on fault codes stored.Google+
Car Problem Reports
Mercedes-Benz SLK280 Camshaft Adjuster Solenoid Failure
Mercedes-Benz SLK280 Problem
Average Mileage: 75,333 mi (45,000 mi - 117,000 mi)
Visitor, 2006 Mercedes-Benz SLK280, 117,000 mi
Vehicle has check engine light on. Also developed shifting from first to drive stalling and not exceed 20 mph.
Intermittent check engine lights. Engine feels like it has a low idle miss, kind of jerks a little bit at idle in drive with brake on. Has occassionally acted as though a cylinder was entirely missing but I also had a different code at that time which could indicate a faulty coil.
Visitor, 2006 Mercedes-Benz SLK280, 45,000 mi
Mercedes said this wasn't why the check engine light was coming on so 702.00 later ugh. But did do recall on solenoid