Engine rattle

Hi,

The noise I hear sounds like the accessory drive belt is loose or dry. (Serpentine belt) I attached a pic of it below. With the engine off, make sure it is tight. If it is, there are two ways to check it. First, remove the belt and start the engine for a couple seconds to see if the noise is gone. Or, with the engine running, take a small amount of water and pour it on the belt. See if the noise stops, chances pitch, or gets worse.

If you do the water test, water will likely splash back at you, so be prepared, protect your eyes, and wear old clothes.

Let me know what you find.

Joe

That is the sound of the serpentine belt slipping as it moves. It could be the belt is worn, the tensioner is weak or a failing accessory or pulley that is causing belt drag. You would need to remove the belt by using a belt tool to move the tensioner and release the belt. Then remove it and inspect it for wear. Personally I would just replace it rather than inspect it. However, I would inspect all of the parts the belt moves. A bad bearing in an idler or any of the accessories could be causing the noise.

New belt runs about $30.00 and other than needing the long tool to move the tensioner it is very easy to change. Some of the parts stores even advertise they change them for free.

That is normal for a failing bearing or weak tensioner. That is why you really want to check all of the rotating items it powers. Nothing is as fun as having an bearing lock up and the friction melts the belt!