I am driving a six-year-old Mitsubishi Colt Plus. The air-conditioner does not dispense cool enough air when it is operating in hot weather, but it seems to be fine in the morning and at night. What is the likely cause?
There could be a number of causes. The most common would be that the system is dirty.
If you have not serviced the air-con in the six years you have owned the car, it is long overdue.
The condenser and evaporator coils trap a lot of dirt. This reduces the system's overall efficiency.
Just as your home air-con needs cleaning, your car's system needs it even more because of the environment it is exposed to.
Another common cause would be that the unit is low on refrigerant. Over time, minor leaks can develop and refrigerant escapes. A top-up is relatively inexpensive, but it should not be the first stop.
A less common cause would be component failure.
Leaks in the above coils would not be uncommon over time, especially if the system is not maintained regularly. The piping can develop leaks too, but that is not as common.
The compressor can also fail, though it often lasts 10 years if not more.
In short, you should send your car for a thorough air-con servicing as soon as possible.