I own a '05 Subaru Impreza Outback Sport. In February '16 I had the head gaskets replaced by my local Subaru Dealership. When the car was returned to me, it was noticeably louder. When I asked about it, they said something about there being more power in the engine with new head gaskets. I know nothing about cars so I leave. A few days later I notice a rattling under the rear passenger side of the car when I rolled over a bump and hear it regularly still. I ask about it every time I take the car in for an oil change. They can never find anything wrong and they can never seem to make my car make the rattling noise.
Today I took my car to another Subaru mechanic. They say they my head gaskets are still leaking and there is a crack in my exhaust pipe. Obviously, I’m going to take the car back to the dealership to fix the head gaskets, but is it also possible that they somehow damaged my exhaust pipe during the first repair? It’s hard for me to believe that these are not related because my car was so much louder when I picked it up from the initial repair. But then again, the problems are at two different ends of my car.