How to Unclog a Blocked Car Air Conditioner?

[VonBraxton]

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.

[VanEvangeline]

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.

[VanJayden]

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.

[ODavid]

In my experience, air conditioning blockages are mostly caused by the filter. Last week, when I turned on my car's AC, there was a water flow sound, and the airflow was intermittent. I opened the glove compartment myself, found the cabin air filter, and discovered it was almost caked with willow catkins and dead insects. I bought a new filter at the supermarket and replaced it in fifteen minutes. If it's a pipe blockage, it's more troublesome—you need to clean the drain pipe, which is usually hidden under the passenger seat. Carefully poke the drain outlet with a soft wire to drain the accumulated water, which can help. If that doesn’t work, spray foam cleaner into the AC intake vent and run the fan at high speed for ten minutes. It’s best to perform maintenance before each seasonal change, especially during the rainy season when bacteria can easily grow. Prevention is key—don’t wait until it’s completely clogged to take action, as it affects both health and the AC’s lifespan.

[DiKira]

Last year, my car's air conditioning suddenly stopped cooling. The repair shop found that the pipes were clogged with mold. The mechanic explained that there are three most common causes of such blockages: the filter not being replaced for a long time turning into a garbage dump, mold growing in the evaporator blocking the gaps, or the air conditioning drain pipe being sealed by dirt. They first used an air gun to blow and clean the pipes, then sprayed a cleaning agent to kill the mold. The most troublesome part was dismantling and cleaning the evaporator, which required draining and refilling the refrigerant. The entire process took two hours. They advised me to turn off the cooling three minutes before parking and use natural air to dry the pipes to avoid moisture buildup and mold. Now, I clean the leaves from the air intake every three months. Developing good habits is more worry-free and cost-effective than dealing with repairs afterward.