How to solve the abnormal noise of Mazda 3 chassis?

Judging from the phenomenon you described, this abnormal sound should be caused by the wear of wheel bearings. When the wheel bearings are worn, the abnormal noise will increase with the increase of vehicle speed. No matter driving in gear or taxiing in neutral, abnormal noise will appear. I suggest you go to the 4s shop to check the rear wheel bearing immediately to avoid breaking down and driving on the road. With regard to the fault of unstable idle speed, it is very important to check the carbon deposition in the throttle body. If there is carbon deposit in the throttle, it will lead to unstable idle speed and make the engine difficult to start. First, check for carbon deposits. I hope my answer is helpful to you.

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