Can somebody please tell me how the hell this happens? I'm trying to see if it would do this on it's own, perhaps if it gets stuck or something, or if my previous shop damaged it prior to install.

Can this happen due to natural causes?

EDIT: This is my tensioner pulley, by the way. My car jumped a tooth (not enough to damage valves I think) and I went in to fix it and this is what I find.

 

i dont see how that could ever happen on its own if the timing belt covers are both on

 

It was definitely dropped prior to install...the corner is dinged and there's scuffing that indicates it's been dropped. Add that to the list of about 15 things that were wrong with my car when I got it back from my previous shop.

 

there is no way that just happens out of nowhere, seems to me like someone doesnt have attention to detail especially after dropping an important part like anything to do with your timing belt

 

I can't believe they have nerve to install it like nothing happened.

 

They probably used a pry bar to tension the belt and bent the pulley.

 

Wow...I bet that's what they did. I'm probably gonna post a massive rant thread on this shop soon so you're in for a treat. This probably isn't the worst thing I've seen on the car.

 

yup, that makes sense! and if a shop is willing to do things the improper way like that, then i would never ever go back there, of course i would confront them about it 1st and maybe just ask how they tensioned it before actually mentioning that it is bent and skipped teeth. you might catch them in a lie, or even worse in this situation for their shops rep sake, telling the truth! lol

glad there was no damage to your motor! i slipped 5 teeth on my intake cam once and did no damage (lucky)