My g35 was overheating. No heat to upper hose and no interior heat from climate control. We were able to get the pump off but I knocked off a piece of plastic on the tensioner where the barrel meets it. It gets worse. We torqued a water pump bolt off and it slipped down the hole where the timing chain comes. Now I can't get the new pump past the chain. I am hoping I can get a magnet and get hold of the pieces tgat fell down. Please help. Very frustrated