Q: Humming noise all the sudden

asked by on February 19, 2017

Last night parked the car and the battery light came on for a sec then the car started making a humming noise. Today the humming noise is only heard while backing up or going under 40 mph. It's been raining. Also just drove 400 miles. 2 weeks ago I took it to the dealer. They said the car is in immaculate condition mechanically

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Hello, There are a number of things that may cause a humming sound. Two things that are more common than most and potentially the most critical are a failing alternator or water pump. Both of these components may produce a whining sound as they begin to fail. If the alternator is beginning to fail, you may notice a drop in voltage, which will be indicated on your voltage gauge. A failing water pump will usually result in a leaking of coolant of some kind accompanied by potentially an overheating engine, which will be indicated by your temperature gauge rising above normal. Should you need further help, please reach out to us here at YourMechanic as we are always here to help.

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