I own a pre-owned crv 03 a/t and lately i have been hearing a knocking sound in the hood (engine?) upon start up in the morning ( or when the engine is cold ). The noise persists for a couple of minutes but then disappears when the engine is warmed up na. Had it checked and repaired in Honda Cars Makati - they said the problem was the tensioner bearing and of course I had it replaced by them. But alas, the knocking noise is still there. Can someone please tell me what the problem might be? and a possible solution?

Thank you in advance for your help.