My new Mazda 3 2010 (5500 mile) is starting to make a horn like sound when I shift gears (MT). sometimes it even does that when I start the car. although this does not happen every time. any ideas where would be coming from??
You should be asking your Mazda dealer. The car is under warranty. Take it in and let them look at it.
The solution is spelled w-a-r-r-a-n-t-y.
Not only do you not need a diagnosis, but if you attempt to give the dealer’s service department a diagnosis, they will almost surely ignore it. If you don’t understand why they would ignore a diagnosis that you provide, then post back for an explanation.
All you need to do is to describe the symptoms, and–hopefully–demonstrate them to a mechanic or the Service Manager (not a Service Writer). After that, it is their responsibility to diagnose and to fix the problem.