Ugh! Local dealership finally got kit to do the Chain and Tensioner for my '10 Police car. I've seriously consider taking my chances and skipping it, because I've felt so certain this extremely quiet 5.7 that runs awesome would come out with some kind of problem. Normally I'm not a negative guy, but I swear I just expected there to be something wrong. I figured it would probably be noise in engine, and/or a leak, or something wrong. Btw, I brought two gallons of Distilled Water and paid for Synthetic upgrade. So, two days later car is ready to go. I start it, and seems ok, but I think I hear a little bit of a noise, but alot of noise around with other vehicles and the garage. So, I drove down the street. Stopped at light, I still think I hear something, so I pull over and pop hood. Sure enough, there is something knocking (best way I can describe it) and it seems to be up front. Obviously, I'm pissed. Turn around and went right back. Had to really control my anger. I know mistakes happen, but why did they call and say it's ready? Did mechanic not hear this noise? Of course he did! I call someone over and first guy is not mechanic, tries to give me a bit of double talk but realizes he's not dealing with a clueless person, automotively speaking. So he calls out a mechanic (not the one that worked on it, he was off that day), and with mechanic's stethascope he agrees noise sounds like up front and under timing cover, most likely. Other dude looks a little disappointed that mechanic confirms what I heard with the naked ear. Still controlling my temper, barely. I did ask why I was called to say it was done when there clearly is a noise. So, back to waiting on the damn courtesy van to take me back home and my car is there and I'm waiting on a call. Anybody have any guesses what could have gone wrong. Seems to me it's a relatively straight forward job, although labor intensive. Thank you for any input.