How to fix knocking & slapping noise in engine compartment with smoke. ?

Please help me to fix knocking and slapping noise and emission of smoke in engine compartment. It is Renault Master van , 2005 model dc1 100. Also when air cleaner removed one of the glow plug had popped out. Could the water gone down the glow plug hole & caused some damage. Or is the turbo blown ? The exhaust fumes are not leaving the engine area, is exhaust manifold blow/cracked ?