"tapping sound"

HI ALL.......
I have just put a 200tdi in my 90 ,the engine has not been run for over 2 years.
I have started it up for the first time today......
The engine started as soon as i turned it over i let it run for about 10 mins and then i heard a tapping sound coming from the front of the engine, if i rev it a little the sound disappeared only to return 20 seconds later.
If i turn it off then start it up again in 5 mins its quiet till it gets warm.

Also i removed belt off water pump and ps pump so just bottom pully turning and it still tapps
it sounds like a loose bracket..!

its had : fresh water,oil,timing belt....
any ideas guys thanks in advance.:doh:

Id check your tappets for a start mate as you could have a sticking one as its been stood so long , ans is there oil getting up to the head ?