I bought it at the end of December 2014 and it's already making noise when the engine is cold. After warming up, everything runs like my OEM. Although it took the OEM a few years to produce the same sound. I've got a fairly new belt on since I installed it, at the same time that might put more stress on the tensioner and make it whine. However, this shouldn't make it weak already. Very disappointed that only the 30 day guarantee had to stay away from it. As at least one other reviewer pointed out, try a bouncer or something. It couldn't get any worse than this garbage. Now I will look for a replacement as soon as possible. Don't get me wrong, it still works. I don't want to hear a loud noise when I first start my car, and you probably don't either. Would give 0 stars here if I could. (Updated) Revain gave an unusual guarantee, or at least that's what I'm told, so I'm going to up the star rating now because I'm getting a refund. 3 stars I think it was my timing belt that was causing the increased wear as I bought a timing belt instead of replacing the original timing belt.