clicking sound

im new to this. but just bought '07 328i a couple of months ago. when the car is started up i hear a clicking sound under the hood. sounds like the belts are a little loose or a little tight. brought it up to dealer a couple of times already to check on it but technician says he doesnt hear anything out of the ordinary. was wondering anyone has the same problem. thanks!

depends on many factors...when you say start up...do you mean first cold start of the day...are you in a closed area (gararge) when you start it..does it happen after first start..can you hear it in open spaces (parking lot)

if it is just the first cold start of the day...nothing to worry about...if you hear it on every start...that may be a problem.."may" is the keyword..

no when the car is warmed up. whether in the garage or parking lot i can still hear it. but at the dealer it is near a highway so they probably cant hear it. but then again it did go into the dealership's garage. they say they put it through a diagnostic test too and cant find anything mechanically wrong. i had a e46 before this one and it sounded like a bmw suppose to sound, smooth and mean. its just doesnt sound right. thanks! if you have any other answers please reply.