Oldsmobile/Buick Repair: heater core location, heater hoses, oil leaks

Question
Sir if you can help me with a couple of problems, first of all i can not find the location of the heater core on my 96 pontiac grand am, i have the part and the ability to change it if i could just find it. I also have a knocking/tapping sound coming from the top of my engine, i have refrenced all the manuals i have and they all say it may be and oil problem, this just started a couple of days ago i have no loss of power and there is no oil leaks or smoke coming from the exhaust i am at a loss on both of these problems if you can give me any suggestions i would be thankful. Justin Barry

Answer
HI JUSTIN ,WELL THE HEATER CORE WILL BE IN THE MIDDLE OF THE CAR UNDER THE DASH IN THE HEATER BOX.IF YOU LOOK UNDER THE HOOD THE HEATER HOSES GO DIRECTLY TO THE CORE THIS WILL GIVE YOU THE GENERAL I DEA WHERE IT IS.AS FOR THE NOISE,AS I DON,T KNOW WHAT ENG YOU HAVE I WOULD HAVE TO SAY .IF IT IS THE INFAMOUS QUAD 4 ENG YOU ARE MOST LIKELY LOOKING AT MAJOR REPAIRS,IF IT IS A 2.2 PROB A LOOSE ROCKER.IF IT IS A 2.5 PROB LOOSE ROCKER  IF IT IS A 3.1 PROB A LOOSE ROCKER.ADD A QUART OF TRANS FLUID TO THE OIL AND THAT MAY HELP.GOOD LUCK PLEASE TAKE A MIN OF YOUR TIME TO RATE ME MOST DON,T TY BILLYMAC