Hi. I've just replaced the head gasket on my 2002 TD5 Disco. Job went tolerably well, and the truck is running again, but.....rather embarrassingly I have a spare part! I know I took it off, but I can't for the life of me see where it came from. Pictures attached. It looks like a water flow restrictor - the hole inside is brownish. Can anyone help please....and more importantly, advise me whether I should be worried that it is not fitted! Thanks in anticipation. Pete