car techie

Custom Search

Accessories     Absorber      Air-conditioning     Alignment     Battery    Car news     Car photos     Carburetor     Clutch      Compression     Color      Converter    Disc brakes    Door    Engine    Gasket   Gear    Glass     Ignition     Light     Maintenance     Oil / fuel



Buy a car
Cold steam

Question : MY Myvi is about two and a half years old. After a year of purchasing it, cold steam came out from the ventilation grill.

I took the car to the workshop twice for a complete air-cond service.

The first workshop told me that my cooling coil was dirty and after completing the servicing, he fixed an air filter before the air intake to the cooling coil. However, this drastically reduced the amount of air coming out of the air vent.

The workshop mechanic also suspected that somehow the warmer outside air had mixed with the cooler air, resulting in steam.

However, he can't detect any leak and the air-cond gas level was OK.

After a week, the problem reoccurred. A drive from Damansara to Pu-chong was enough to create steam.

So I took the car to another work- shop. After a complete check, the workshop mechanic told me that the thermostat was faulty and in order to prevent freezing, he decided to install the thermostat a further bit away from the cooling coil. This time it worked but the compressor cut in and out often.

Eight months after that, the steam came out again.

When I asked around, the workshop told me that it is a common problem for the Myvi.

What am I supposed to do as every time when steam comes out from the ventilation, it is so frustrating and affects my driving concentration?

Answer : What is coming out of the vent is not steam but 'fog', i.e. condensed water vapour caused by the very low temperature in the evaporator.

There are two components in the air-conditioning system that always cause confusion.

1. The thermostat -- which controls the compressor and which cuts it in and out at a pre-set temperature.

2. The expansion valve -- which allows the liquefied refrigerant to expand in the evaporator and so give you the cooling effect.

The usual problem is that the expansion valve is not adjusted correctly or malfunctioning such that the flow is too high, resulting in the temperature dropping below zero degree C in the evaporator.

This causes the water vapour in the air flowing past the evaporator fins to start to freeze, giving the 'fog' effect and also smell like the freezer of a refrigerator.

If this continues, the evaporator may freeze up completely and there will be no air flow and ice will be seen on the evaporator fins. The solution is to replace the expansion valve if it cannot be adjusted.

The thermostat could also be at fault if it stays on for too long but if it is replaced and the problem still occurs, then the cause is most probably the expansion valve.


Cold steam

Dashboard leak

Smoke comes in

Lack of cool air

Night problem

Fan poser

Air-cond servicing

Air-cond service

Faulty air-conditioning

Air-cond leakage

Air conditioning fault


Air-con 1



Spark plugs
Timing belt


Sites of similar field are welcome for exchanging links