Serpentine Belt Tensioners

How often does the serpentine belt tensioner need to be replaced? I am looking to do a timing belt change and was wondering if I need to do this as well. I have almost 160k mi on a A4 Jetta.

(I tried doing some searching to see if this had been asked but didn't find anything very quickly)

I would say it should good for 200-300K.

However, if the Alt. pulley goes, this will weaken the tensioner. And many replace the tensioner before getting to the bad Alt. pulley.

I did a little looking and found that the timing belt kit from Bora Parts has an option for adding a serpentine belt tensioner to their kit and in a parenthetical state that it should be changed every 150k to 200k mi. So who do I believe?

http://shopping.boraparts.com/product_info.php?cPath=21_26_31_41&products_id=30

GgOTi said:

I did a little looking and found that the timing belt kit from Bora Parts has an option for adding a serpentine belt tensioner to their kit and in a parenthetical state that it should be changed every 150k to 200k mi. So who do I believe?

http://shopping.boraparts.com/product_info.php?cPath=21_26_31_41&products_id=30

Click to expand...

Well, maybe get the kit with it and keep the new tensioner on the shelf, until the one on the car goes bad.

Wouldn't I want to replace it before it goes bad...

GgOTi said:

Wouldn't I want to replace it before it goes bad...

Click to expand...

Then why ask how long they'll last ?

Because I need to know if it is 150K mi or 300K mi. I would be a fool to replace it more often than what is necessary, and I would be asking for trouble if I delayed replacing it too long.

It, like many items on the car are not good one moment and broken into pieces the next, most of the time. With the tensioner for the serpentine belt, it will likely make noises before it flies off, giving a warning of what is to come.

True, things do break without warning and long before they should. I have seen posts of timing belts breaking short of the mileage for changing. And seen posts of some running timing belts long past their due mileage. Due to the costs if the TB fails I would not run a TB long past it's change point. I do change the water pump with the TB on my TDI. But I had a Mazda that DID NOT call out for a new water pump with replacement of the TB. The Mazda's org. water pump lasted past the 347,00 miles I put on the car.

Some of the wear items on our cars do not have HARD guidelines for change out. On these items, each owner should do as they feel comfortable for them.

Thanks, but that really doesn't answer my original question. How often is the belt tensioner supposed to be replaced? Or is there not a definitive change interval?

Just my take on this ..
I hate the plastic pulley arrangement, where i cannot replace the bearing, so at 150 K km's i got an old pulley, and had an aliminuim pulley turned up, and pressed in an SKF bearing. Upside to this is, when it start singing agian it is a cheap bearing replacement ..... cost of the alumina pulley less than new vw pulley .

__. It won't answer your question exactly but see my posts from the past few weeks on the tensioner. Those threads should give you valuable info that should serve as helpful background.

(Edit - Also look for threads on alternator pulleys.)

For what it's worth most people who have them fail have been in the 150-250k miles range. You can always replace it when it goes, or for those that like to do preventative maintenance, it's a good idea to replace it when you're doing 180-200k TB change. If you have to change it again at 400,000 miles then that isn't a huge deal; most people won't keep the car that long and feel that getting it taken care of at 200k is better than ignoring it and then having to change it at 225k (or whenever it fails).
Hope that makes sense...
-BB

Don't replace it until it needs it. It's not a maintenance item.

My idler failed at 150k and my tensioner at 165k, hindsight is 20-20 but I would have replaced both at the same time. Especially since when the tensioner went, the belt got hot and melted my 'new' idler.

To your question "How often is the belt tensioner supposed to be replaced? Or is there not a definitive change interval?, the answer is none. Just replace it when it breaks. Hopefully, it may outlast the rest of the car.

GgOTi said:

Thanks, but that really doesn't answer my original question. How often is the belt tensioner supposed to be replaced? Or is there not a definitive change interval?

Click to expand...

I have not seen a recommended mileage or time for replacement of the tensioner, so " not a definitive change interval " looks to be correct. What I had posted was what seemed like a good number for those that did NOT have an Alt. pulley fail. As this would sink the tensioner quickly.