HowsTheHonda

I got my timing belt & water pump replaced about 2 days ago, when I got my car back I heard a rattle & my car was louder than usual.

Popped the hood & bolts to my headers were not tightened, so I tightened 'em up, still same issues, rattling & loud car.

From what I've heard from other people, they say it's a bolt to the alternator, timing belt was installed wrong, motor mounts are loose etc...

Anyone have really helpful information as to why my car is doing this?

It's never been this loud & that rattle has never been that loud as well.

Rattle is the loudest when going up a hill.

and it's only heard on the drivers side.

S2BumpsticksGSR

Sounds like the mech forgot to tighten motor mount and/or installed the timing belt a tooth off of where it should be. Lousy shop, sorry. You had to retighten exhaust nuts/bolts! Wow. They shouldn't have had to loosen them in the first place lol. Let me guess, this shop is mostly a domestic(gm/ford/chrysler) shop. I wouldn't go there again.
Edit: check the cat converter heat shield and donut ring gasket between header and cat. If they took this stuff loose, for whatever reason, they could've forgotten to retighten this as well. I hope they did the w/p install w/o forgetting to tighten stuff ie; timing belt tensioner...

strategy400

Check the lower alternator pivot bolt (the big one) for tightness or if it fell out from being left loose. That will definitely cause a rattle.