Had my water pump reolaced now my car runs really loud and hard and rattles and shakes.

What is your question?

Mechanic wanted to replace the timing belt when he replaced my broken water pump, but I told him I already had my timing belt replaced 3 years ago. When I picked up my car and drove it, the engine sounded really loud like there was no muffler, and the car was shaking and rattling. Not that quiet humm you get at a stop light which I previously had. Could they have moved or messed up the timing chain when they fixed my water pump?

What makes this problem better or worse?

Nothing

How long has your 2006 Kia Sportage had this problem?

As soon as the repair was done and I tunred on the engine