How to Unclog a Blocked Car Air Conditioner?
3 Answers
For dirt blockage, if it is not too severe, you can replace the dryer filter. If it is very severe, you will need to clean the impurities in the system pipeline again, evacuate the system, and recharge the refrigerant. For minor ice blockage, you can apply a hot towel to the ice-blocked area.
I've been driving for over a decade and have encountered several instances of air conditioning blockage, which is quite annoying. That time when I was on a long drive, I suddenly felt the airflow from the AC weaken, and the cooling became insufficient. I first checked the AC filter myself, and upon opening it, it was completely clogged with leaves and dust. I removed the filter, vacuumed it thoroughly inside and out with my home vacuum cleaner, rinsed it with water, dried it, and reinstalled it. It improved slightly but still wasn't ideal. The next day, I specifically went to a repair shop where the mechanic used an air pump to blow out the AC ducts for a while, removing a lot of dirt and debris, and also cleaned the evaporator. They recommended doing a deep cleaning of the AC system before every summer, especially for older cars that tend to accumulate more grime. Now, I've made it a habit to replace the filter every six months to avoid similar issues.
A while ago, my car's air conditioning got clogged, with obvious symptoms like a sudden drop in airflow from the vents and a musty smell. I tried replacing the filter myself, but it didn't help much, so I had to seek professional help. The mechanic used an endoscope to inspect and found a layer of yellow sludge on the evaporator surface, which they said was a mix of tobacco tar from smoking and dust. They used a high-pressure steam cleaner for nearly half an hour and applied a specialized cleaning agent to dissolve the grime. Finally, they dried the pipes with an air gun, draining out half a bucket of dirty water. The mechanic explained that if the blockage had been deeper at the expansion valve, it would have been more troublesome, requiring the dashboard to be dismantled for repairs. Such blockages often occur due to long periods without filter replacement or frequent exposure to dirty air, and they recommended using the recirculation mode more often in poor air conditions. Since then, I've been checking the air conditioning system every quarter.
