Advice please, I have a 2003 iveco tector six cylinder engine mixing the coolant with the oil. The problem happened from lack of coolant , I’ve replaced the damaged items I discovered, radiator, oil filter housing, oil cooler and a popped out freeze plug, the engine runs fine but I still have the problem. If I drain the oil and leave the sump plug off and fill the coolant up I get the coolant coming out of the sump when I release the vacuum on the coolant, it comes out reasonably quickly which suggest to me it’s probably not a gasket. I read a post on here that someone had replaced freeze plugs under the rocker cover to solve the same problem as this. It seems a bit odd to me but are there freeze plugs under the rocker cover? I know it could be more terminal than this but just trying every possibility. Any advice appreciated, thanks in advance.