Noisy NG 2.3e 10v

[ASBOAUTO]

Hello all, this is my first post hope its successful one. Here we go. I am the proud owner of an L plated Audi Cabrio 2.3E 10v 5 cyl NG Engine, i am experiencing a couple of problems with it, first of all when ticking over there is a quite intermittent ticking in equal timing every 5 secs or so, and when I accelerate it sounds as if the exhaust is blowing, i have had the exhaust replaced prior to this from the catalytic convertot to the tail pipe and my exhaust mate has also checked it and said its fine no blows. I know these engines have a distinct sound but when im drivin alongside central reservation barriers it sounds terrible, the bottom end of the engine also seem to make a similar sound as I accelerate. There is no loss of oil or any smoke it starts fine unless u drive for couple of minutes and then try to start it again in which case it turns over about ten times or so.Heres the list of things ive had done.

New ht leads and plugs
New oil filter
New electric window switches where required
New Radiator
New Exhaust from the cat back to tail pipe
New Offside Caliper
New Discs and pads on both rear wheels
New Leather Gear Gaitor
New Expansion tank Cap
New timing and alternator belts

As u can see I am trying to get this old beast to keep running and running as its my baby, it has only covered 97000 thousand miles PLEASE HELP ME.