I went to start up my stang yesterday after driving it hard earlier in the day. It start clicking really loud, kinda like when my fan was hitting on the fan shroud. Popped the hood and it wasnt the fan shroud . Seemmed to be coming fom engine alil louder on the drivers side , like under the intake or the valve covers, couldnt really pin point it. When I listened from under the car it was clicking maybe louder from there. Any ideas on wherer to start or whats going on??? thanks