Hello, I have 2006 L322 4.2 SC Range with heating problem.
After engine heats up till its operating temp, i have very little heat in cabin. Its not cold, but its barrely hot. When i try to adjust temp, its almost did not change. For example: i set 24 degrees (celsius) for both sides and its blows somethink like about 20-22 degrees air. When i change it to max heat, it blows almost the same as if i set to 24 or 22 degrees. So almost no change in temp.
If i drive at higher speed (~100km/h) heater blows hotter air. When speed slows down, heat also goes down. Sometime its start to blow cold air for minute and then again little bit hotter.
Car also have FHB (yes, petrol with FHB )
I made experiment: in the morning, start FHB for 20mins. After that i check engine temp. and it was ~35 celsius. So maybe my FHB changeover valve is bad? I think FHB should only heat cabin?
I have no coolant leaks. Engine is not overheating. No hvac error codes.
Maybe there is a problem with changeover valve or heater valve? Or both?
Maybe someone has an idea?