I have replace a many belt tensioners in my 2000 LT 4x4 blazer, (106K) the one on it now is going bad again (Its bounceing around) One day I will learn NOT to go to Auto Zone for that part and many other parts for that matter. Oh, one made some noise but the others did not not, I check everything under the hood when I check fuilds and thats often. And thats when I catch it bounceing. The best thing that I have replace under the hood is my serpentine belt made by Good Year, its 10 yrs old and still looks good, has a life time warr on it.