Hello, I'm having trouble with my 2003 S6. its a 4.2 v8 with 105k on it. I went to start the car today and nothing. All the lights are on in the dash, but the engine wont turn over. So i took the battery out and had it tested, and its perfectly fine and had a full charge. Naturally I'm taking the battery and alternator out of the possibilities since the battery was fine. After i put the keys in and turn them to the "On" position all the normal lights light up on the dash, but when i attempt start it all i hear is "buzzing/vibration" sound. I've tried tapping on the starter to see if that would at least get it started once and I've also tried starting it in neutral which neither worked. Does any one know if this would be the actual starter or just the solenoid? Or any other suggestions on how i can get this fixed? thanks

 

Had the Starter, battery and alternator tested and are all good. does anyone else have an idea what it could be?