My car makes noise during idling only. It has gone close to 100,000 miles. The noise is coming from the outside of the car, from its bottom part. It is a rattling noise similar to the sound made by tin cans. This happens frequently, especially on the first car startup of the day. It gradually becomes less loud after some time. There is another helicopter-like, deep rattling sound that is noticeable occasionally. What could be causing these noises? Thank you in advance.
The rattle at idle could be caused by a variety of issues, such as any loose parts or panels, fuel injector noise, or the engine top end. The deeper rattle could also be caused by a few items such as a drive shaft, wheel bearing, or the engine itself. This could potentially be a serious safety hazard, so it would be best to not drive the vehicle until it is inspected. To prevent this from getting any worse, a qualified technician, such as one from YourMechanic, will have little trouble diagnosing your rattling noise and performing any repairs required.