Thanks for the replies fellas, might just be worth cleaning it now and then monitoring it as I go. Does anyone know if this is the same motor as the amarok? I've got the 340NM version, twin turbo's (if you want to call them that, lol)

Overall the van is good, I'm a mobile truck mechanic and its pretty loaded most of the time. Just want to stay on top of the maintenance as its gotta last me 5 years or so. Not bad on fuel either considering its loaded 100% of the time.