Went to start my C240 auto yesterday. I turned the ignition on and accidently just touched/activated the starter motor, but not enough to actually spin the engine. I took the key back to ')' and tried again. This time the starter activated, engine started, but with a terrible screeching / grating noise - quite deafening in fact! I turned the engine off immediately but the noise carried on with the key back at '0'. In desperation I turned the key back around as if to restart the car and the noise stopped. I waited a minute or so and it started fine with no noise! I don't know whether I upset something by initially activating the starter motor? Been fine today, but was quite alarming! Any advice, quite new to this model. Thanks.