Noise under the timing belt cover

[Larman98]

I have a 98 caravan with the 3.0 v6 and recently i here a noise after startup that sounds like a 2 dry pieces of metal coming together real quick and then it goes away, it also comes ocasionally when your driving and now there is noise that souds like a bearing or a dull rattle. The outer serpintine belt and all pulleys are free and with the belt off they all free wheel with no signs of problems. I had the timing belt and the water pump replaced about 2 years ago and i do not know if they replaced the timing belt tensioner - could this be the culprit? The engine has no sounds coming from it that would make me think there was a cam bearing going out in fact it is still a stout motor when you rev it up. The noise iseems to coming dead center between the right and left cylinder head but i have not pulled any covers yet.