Right, just before i try and replace a noisey tappet by replacing the lot, i thought i'd just run it by you guys as there are some pretty clued up guys that have saved me a small fortune with my Golf turbo.

Any ways its a AUM golf 1.8 turbo, and the problem lies in what i have been told is a noisey tappet but i'm unsure as it doesn't do it all the time.
If i start the car, there's no noise, ticks over perfect, and is still quiet untill the engine gets hot (i'll say hot but its just normal operating temp) then it starts to "tap" from the top end somewhere. But, if you rev the engine the noise stops but returns when the revs drop back to tickover. If the engine cools and i try again after an hour the noise has gone but comes back again when hot. Driving, when the car is up to temp, the noise can't be heard but when stopped at traffic lights or turns and the engine is on tickover, the "tap" is back but again, is gone when normal driving resumes. Now in my eyes, if the tappet has failed it would but noisey from the start and be there thru the rev range....or am i just talking boll@x?
Cheers