It sounds like what happend to my car. I had some loud slapping noises coming from the valve cover area. It ended up being the main bearings. Had to replace the engine. The only thing different is that i DID have some driveability issues.

Former owner: 1999 Contour SE Sport Current: 2000 Eclipse GT There are three ways to do things: the right way, the wrong way, and the Max Power way! Isn't that just the wrong way? Yeah, but faster!