Tensioner went bad and belt was destroyed. Bought a Dayco belt and aftermarket tensioner. All pulleys seem to be lined up but when accelerate the engine the belt flies off. Any help would be greatly appreciated. Pulling hair out and don't have any to spare

 

Check the pulley lands and Grooves carefully and mAke sure that they match the belt.

 

Is the belt on like the guide under the hood?

 

"invest" in a good belt. just kidding man. make sure if you have a/c, that you bought the belt for a truck that has a/c. the same goes for non-a/c. how much slack do you have in it? do you have good retention in your tension pulley? double check the way you routed it and make sure its according to the diagram sticker under the hood. Also, I would take my old belt, piece it back together and make sure your new belt is the same length. there might be a small difference since the old belt stretches out with time. Lastly, someone could have wanted to go to there break early and they gave you whatever belt. keep me posted on how that turns out.

 

I always make sure to use a soft (brass/bronze) brush and some solvent cleaner on the grooved pulleys before I install a new belt. Many times I've seen them pretty clogged up. Prolly not your problem but it wouldn't hurt.

 

I'm thinking your tension pulley is bad. what brand is it? buy a goodyear. there only $50.