hi guys,long time since I've been here....I've a 2003 td4 pre face lift....I've attached photos..got home last night to find no coolant in header tank...gad a quick look with torch and found the leak in photos..firstly the car didnt over heat and needle didnt rise above mid point at any time.....any body seen a leak from the bung/cylinder head on the right hand side of engine,behind/just below the egr pipe...any advice on what the bung is, is it terminal? am I looking at cylinder head? replacement or can it be filled with metal putty?...thank you