07 2.0 Mazda 3 engine abnormal noise is what situation?

First, the wheel or flywheel of the starter is missing teeth, which leads to abnormal sound when starting. This needs to be checked in the 4S store and can be claimed. If this situation is not solved early, it will lead to more serious flywheel wear and burn out the starter.

Second, the friction between belt and pulley. We should pay attention to this situation. There may be two reasons for this. First, the timing belt is slack, and the solution is to adjust the tensioner. The second type is that the timing belt is missing teeth and needs to be replaced. If the timing belt problem is serious, it will lead to serious problems such as crankcase crankshaft fracture.

I suggest you go to the 4S shop to check it out.