[QUOTE=jwsoaa;941031]First of all, if you take the car to a dealer, you may as well sell the car - they are not going to fix it, but they will cost you a lot of money. Find a local garage you trust, best would be one known for Mercedes or German experience but a lot of things about the car don't really require it. I gotta tell ya, if you are one who goes to a dealer at the drop of a hat - you bought the WRONG car! See my sigline - nuff said.

Second, the Check Engine light means somethign very simple: The ECM has detected a sensor reading that is out of range. The only way to respond to this is to read the code or get someone to read the code.
Most auto parts stores will read codes for free, get the code(s) and come back here and post them, we will take it from there. The codes from the check engine light can be frustrating to deal with, and other times, can be super easy to deal with. Those of us who have been here for years actually have seen most of the common codes the car will throw, and frankly, we often know what it is just based on the code. (Our cars are kinda predictable!)

Better yet, go get a code reader, I like the BOSCH OBD 1100 - it is super easy to use. There are better scanners, but if you are not a big "tech" guy, there is no need to buy a better one. I've used my '1100 several times on my car and truck - love it as I hate being dependent on a garage or parts store for 'knowledge'.

Get the codes, come back here, post them - and we can probably help. And yes, if the car is running fine, don't worry about it. With that light on, you can't pass an emissions test, but other than that, you are fine - if the car runs fine and the temperature gauge is normal, you are fine.