Dear sir, I have Epica 2.0 automatic 2007 model.Problem: During cold start i heard knocking like noise and when car get heated,its gone and becomes smouth. But during this, when i run/accelerating car i heard tic-tic sound & when release accelerating no sound.. This tic-tic-tic sound comeing in all situation when i accelerating car either ideal run or normal running condtion.. Can you please give what was problem> is it normal or regular..