Thanks for taking the time to read...
I just purchased a '99 SLK230 with 34,900 miles with a superchaged
4-cylinder engine. The car appears prestine, but after driving it for a few weeks I am starting to become concerned about the engine. When I inquired on the vehicle service history, the one owner before me never had any maintenance other than oil changes performed. So I paid the Mercedes service center to perform a Flex B service (inpect, top off, etc..) and asked them to pay close attention to the sound the engine is making. They changed the oil, and wiper blades and $400 dollars later I got my car back with the same irregular idle and knocking sound in the engine. They said they didn't find anything out of the ordinary - not what I was expecting to here.I'm not an expert by any means, but I've owned a lot of different cars. All of my well maintained car's idle were smooth and steady with no knocking sounds from the engine. I'm also convienced the car should be faster than it is - 185HP in a 3,000lbs body should be zippy, but my 2003 4-cylinder Mitubish Outlander SUV (which I traded because I hated) appeared quieter and nearly as fast as the Mercedes I just bought.
I want the car to idle smoothly, get the knocking knocked-out, and perform like a sports car. I'm not convinced the Mercedes dealership service center gave me a fair evaluation of my concers. Can anyone provide advice on how I can get these things taken care of without spending $180 per hour at the Mercedes service center that doesn't think there is anything wrong to begin with? Or should I just accept that a now over 4-years old car with now 35,100 miles should idle irregularly, make knocking sounds, and perform under par?
Thanks, - Matt