If you cant see a leak then the engine must be using the oil internally,are you getting clouds of blue smoke from your exhaust?try removing turbo inlet and feel for play in the impeller,it may be sucking in oil through the seals,other than that it may need an engine strip to determine your problem which will be expensive and it may be worth working out whether a 2nd hand engine would be your cheapest option.Personally I would trade it in and don`t but another Renault,you are asking for trouble!
cdc, June 2012
