Neighbour's car, 85,000 miles. Losing coolant. Tiny bit of condensation mayonnaise on cap but none elsewhere (as far as one can see inside) and the oil looks OK. Coolant looks OK too. Engine sounds fine and the 'smoke' smells like steamy coolant, not burning oil. Are these engines known for CHG failure or could it be something to do with the intercooled turbo? Any Renault experts out there? I would be grateful for opinions re diagnosis.

This engine seems to have been around in many different cars for a long time, but perhaps 80 - 100,000 miles is all one can hope for?