Could Your Temperamental A/C Be Down to a Faulty Evaporator Valve?
Is the air conditioning system on your car temperamental? For example, does it start off with a refreshingly cool blast and then seem to get warmer as you head off on your journey? This could be traced to a number of different reasons, but you'll want to get to the bottom of the problem as soon as possible with summer fast approaching. What could be going on within the system?
Moisture and Damage
Contrary to what some people believe, water is not part of any air conditioning system, and, in fact, humidity is enemy number one. If moisture does get into the system, then it can cause a chemical reaction that leads to corrosion, leakage and ultimately failure. The best way to guard against this is to make sure that you service the vehicle on a regular basis and, crucially, ensure that the refrigerant is kept in good condition. If it happens to break down through the presence of moisture or old age, then it will not be able to do its job properly, and failure will ensue.
Breaking down
This may be the root of the problem if your A/C system appears to be okay one moment and then blows warm air the next. The expansion valve may no longer be able to do its job due to the presence of contaminants.
Sticking Valve
The valve itself has a relatively narrow opening, and if there is any rust, sediment or contamination in place, then it may struggle to open or close. Consequently, this will affect how much refrigerant gets into the evaporator. It may also be stuck in one position or another due to the fact that it is not receiving much-needed lubrication from the refrigerant itself. Again, if the refrigerant breaks down or is contaminated by moisture, then it will not be able to protect the valve at all. The valve may be in the correct position when you first start the car, and this may allow cool air to flow. However, it will be unable to activate if it is clogged and this will cause the system to freeze over.
What to Do Next
If it's been some time since your A/C system was serviced, then your evaporator valve may be beyond repair. You need to take it into a mechanic so that they can change the offending part and repair any other damage before you can continue.
For more information about car repairs, contact a local shop.
