Both are used to keep tension on the engine serpentine belts so that they can drive the various engine accessories.
Serpentine belt tensioner pulley noise.
The serpentine belt is given the proper amount of tension by a device called a drive belt tensioner.
The tensioner is basically a pulley connected to an adjustable pivot.
A drive belt tensioner is a pulley mounted on a spring mechanism or adjustable pivot point that is used to keep tension on the engine belts.
The pulley itself has an outer ring and an inner bearing.
Pulley misalignment belt misalignment on pulley defective tensioner or bearing wear in tensioner idler or driven accessories belt noise can be hard to isolate as the sound may seem to be coming from an accessory drive such as the alternator or air conditioning compressor.
This video is for the following repairs belt tensioner noise belt tensioner bad belt tensioner symptoms belt tensioner bad belt tensioner quick fix bel.
If the pulley is making noise either it s the result of a bearing failure or the spring is not providing the proper tension.