Hi ecaterinis1. Welcome to the forum. You are expecting way too much in the way of foretelling the future. There's no way to tell when parts like that will fail. Some failures on some cars can be predicted based on mileage and past history. Timing belts are one example, and GM products have a ton of "pattern failures". But 6,000 miles ago there was nothing wrong with your tensioner so why would you replace it? Also, the bearing or bushing inside a tensioner's pivot is sealed and hidden. The only clue, by looking at it, that it is defective is if the belt is walking off-center or is starting to shred on the sides. When that starts to happen, belt failure is usually only a few miles away, not 6,000.
Very often, when the mechanic IS aware of things to look out for, (Honda timing belts breaking at 60,000 miles is a perfect example), and he recommends preventive repairs so you don't break down on the side of the road, he is accused of trying to sell you parts you don't need. Your tensioner is not one of those parts that can be predicted. The tensioner on my '88 Grand Caravan with 379,000 miles is original. I also have replaced defective ones on vehicles with less than 3,000 miles, so you just can't tell.
To look at it from a different angle, how would you have felt if the mechanic said, "there's nothing wrong with your tires, transmission, belt tensioner, engine, power window motors, etc, but I think you should replace your wiper motor. It's working fine yet but it's going to burn out in 6,000 miles". For that matter, if part failures could be predicted, we wouldn't have need of tow trucks. Just bring your car in for repairs a day or two before the breakdown occurs. Wouldn't that save a lot of headaches? :)
Wednesday, September 8th, 2010 AT 6:51 PM