According to this Gates bulletin, automatic belt tensioners should be replaced with every belt replacement:
http://blog.autoupkeep.com/wp-content/uploads/2009/08/Gates_BeltTensionersRole_Final.pdf
Per the Gates bulletin, noise from accessory drive belt systems are often caused by either pulley misalignment or the start of belt tensioner failure.
In the past, I have seen cars with slightly noise belts that were cured with a new belt only. However, lately, I have also seen a number of cars with badly worn belts that exhibited no noise at all.
Recently, I came across an Accord with a moderately worn serpentine belt that was making some squeaking during cold start-up. On this car, the tensioner pulley also had a borderline-excessive amount of play. Although the new belt has quieted the system completely, I have already obtained a new OE tensioner and plan to install it given what I’ve learned from the Gates bulletin.
Based on the information from Gates and your past experiences, is it truly necessary to replace the auto-tensioner with every serpentine belt replacement? Logically, tensioners should lose some effectiveness with age, so arguably a new tensioner should allow the new belt to have the same service life as the first one. However, it is possible that Gates is trying to sell more tensioners…
http://blog.autoupkeep.com/wp-content/uploads/2009/08/Gates_BeltTensionersRole_Final.pdf
Per the Gates bulletin, noise from accessory drive belt systems are often caused by either pulley misalignment or the start of belt tensioner failure.
In the past, I have seen cars with slightly noise belts that were cured with a new belt only. However, lately, I have also seen a number of cars with badly worn belts that exhibited no noise at all.
Recently, I came across an Accord with a moderately worn serpentine belt that was making some squeaking during cold start-up. On this car, the tensioner pulley also had a borderline-excessive amount of play. Although the new belt has quieted the system completely, I have already obtained a new OE tensioner and plan to install it given what I’ve learned from the Gates bulletin.
Based on the information from Gates and your past experiences, is it truly necessary to replace the auto-tensioner with every serpentine belt replacement? Logically, tensioners should lose some effectiveness with age, so arguably a new tensioner should allow the new belt to have the same service life as the first one. However, it is possible that Gates is trying to sell more tensioners…