I'm new to this forum and hope someone might be able to help. I have a 2003 Discovery TD5 diesel auto. Was topping up water earlier today and found oil in the coolant reservoir. Been topping up the water for a while as seem to have small leak. No oil found until today though. Have been told it could be either the oil cooler or head gasket. Does anyone know how you can tell which it might be as it will be an expensive guess. The car has done 72k miles and had a new engine put in under Land Rover used car warranty at 50k miles 18 months ago. Also have had a wierd gurgling sound from engine area for sometime, mostly when corning - again, any suggestions. Had so much wrong with this car, its almost been rebuilt ! Thanks for any help - Paul