Small Knocking Sound

you sure its not pinking? it sounds abit suspicious how it cahnged noises and running when you changed the belt?

simon

I would check all the timing marks are correct - flywheel, fanbelt pulley, camshaft, just to be sure everythings aligned correctly. Then take the plugs out and check the compression with a compression tester. Bent valve would be likely to show low compression on a cylinder.
Be sure tappets are right - if hydraulic then flush em or change them ( a replacement set is fairly cheap) - if shims then check clearances and set them right.
Also make sure ignition timing is correct - this can cause tapping type noises and poor performance if wrong. Also check around the manifolds with a small length of hosepipe -stick the other end in your ear and listen for blowing - blowing straight off the manifold gasket can sound a bit like a tap…
Good luck

Success!!

I did some research on the timing and found that the way i was doing which was stright from the haynes manual was useless. I found some much better pictures and instruction. After redoing the timing properly the engine is running very well and im very happy with it.
Thanks for the help.

Excellent - it's fixing something like this after a struggle that makes DIY car repairs so much fun!
…Actually…it's much more fun if you can fix them without any hassle, but then life would be too easy, and you'd have to watch more telly :?

Hows about advising where you got the timing info or posting how to do it?

I find it hard to time my 1.6gti due to the waterpipe above the peep hole on the flywheel.