My diesel engine at 94000 km with good service record has exacly the same issue, no indication engine was overheating, gauge normal, no white smoke or anything but coolant would rise on the reservoir tank..combustion test determined there is combustion gas present in the cooling system..had to take it back to the dealership to be sorted
I had a block test performed and it went from blue to yellow but I have no white nor black smoke coming out of the tailpipe and I do not have the bubbles in the reservoir either. Is it still a gasket that is bad on the engine?
