Rattle coming from front of engine at idle? (Video)

Hey guys, was hoping someone could help me identify this noise. It's definitely coming from the front of the engine, it sounds like a rattle more than a growling/grinding noise. I can't normally hear it while driving, but I notice it when I pull the car into the garage and then it's fairly loud. It doesn't seem to change much if I rev the engine. I just had the entire cooling system redone, so if it was a pully I would hope the mechanic would have noticed that, but its a busy shop. Here's a link to a video I took of the noise, any ideas?



http://ift.tt/1ErlU1V