I had the exact same issue when rebuilding my brothers 1.8T A4. I timed the head sprocket and crank perfectly and turned her over by hand to get the oil into the cam followers, however I wasnt aware that there are actually timing marks stamped on the rear of each cam which need to also line up. As a result I bent all 8 exhaust valves. My guess you've done the same. See link below to a thread that will show you the rear cam timing marks. Its very easy to miss as most cars time on just the front cam and crank.

http://www.passatworld.com/forums/61...tensioner.html

See below link also to a video of my brothers car turning over.....at the time I couldnt work it out so removed the head and discovered all 8 exhaust valves were bent....gutted as I had just replaced them all!

If your engine sounds the same on turn over the exhaust valves are bent mate sorry.

http://s182.photobucket.com/albums/x...10205-1132.mp4