So I recently bought a 2004 Mercedes Benz C230k sedan for a steal with minimal issues except for one that has been annoying me to death. The key will always open the doors/trunk etc. but when i enter the car and put the key in to the ignition, nothing, it wont even turn. So I take it out and put it back in again. Sometimes MANY times, sometimes a few, and finally it will recognize the key and start. I have also noticed it happens a lot more often and takes many more attempts when it is really hot outside. I wouldn't really have too much of a problem with it as I usually try to avoid being in a rush but when I am, and when its hot outside+black seats and interior, it gets VERY hot in the car even with the door open and I start getting sweaty while trying to start the car. When I first got the car, for the first few days the key would always turn, but when it would get to the start position it would make an attempt to start, and not be able to, when i would first turn the key all the lights would turn on on the dash and when it wouldn't start they would all just turn off as if I hadn't even turned the key. This doesn't happen anymore but I though I would mention it. So please help me out, Im kind of an amateur with all this stuff and I would like to learn. This issue has been annoying me so much and I would rather not take it in to a dealer because I'm a little tight on funds at the moment.

Thanks

 

The first part of your description makes it seem like a bad EIS.

The second part where it fails to start can be many things. Something extremely simple or not so straightforward.

 

That's exactly what I was dreading. Isn't that part very expensive to replace?

 

The only part in there I can relate to, is starting while it's hot. I have issues here and there with that and I've been told it's the Crankshaft Position Sensor. A cheap part to get, and not all that expensive to replace at a shop. Good luck!

 

Thanks, have you tried this? And its relatively cheap so I will try it this weekend. Is the installation difficult?
Edit: The more I read in about the effects on the car of a bad crankshaft position sensor, the more I see that this could be the problem. Problems starting the car and sometimes when it starts it idles for a few seconds and just turns off on its own.