What Causes Intermittent Car Air Conditioning Issues?

[DeAshley]

Intermittent car air conditioning problems may be caused by the following reasons: 1. Lack of Freon: Check for possible leaks by dripping water at pipe connections - bubbles will appear at leakage points. Repair the leaks and refill Freon at an auto repair or maintenance shop. 2. Dirty filter: Locate the bypass valve on the filter base; it opens when pressure difference reaches a certain level (engine oil normally flows through this passage to the main oil pipe). Use automotive lubricant on related components. 3. Insufficient antifreeze: Visit a 4S shop or auto repair center for professional inspection. 4. Aging AC core: Replace the old AC core with a new one purchased online. 5. Excessive refrigerant pressure: Check pressure with gauges and clean the condenser thoroughly. 6. Insufficient refrigerant (snow seal): With engine running, verify pressure readings and inspect the cooler's operation - weak cooling or airflow indicates low refrigerant levels, which requires professional replenishment.

[EmilyFitz]

I've encountered this issue before. The AC blowing hot and cold intermittently can be really annoying, likely caused by refrigerant leakage or pipeline blockage. When refrigerant is insufficient, the AC pressure drops, causing the compressor to work intermittently. Additionally, a slipping compressor clutch can also lead to this situation - pay extra attention if you hear buzzing noises from the engine compartment. Another possibility is electrical issues with the AC system, such as burnt relay contacts or poor temperature sensor connection. Like with my old car, the AC would cut out on bumpy roads but work fine on smooth ones. Don't forget to check the blower motor resistor too - it controls fan speed, and when faulty, the airflow becomes inconsistent. These problems are best diagnosed with professional equipment, and any repair shop should be able to handle them.

[RyderLynn]

As a mechanic with ten years of experience, I often encounter cars with intermittent air conditioning issues. The most common problem is a stuck expansion valve, which controls refrigerant flow—when it gets stuck, cooling performance becomes unstable. Another frequent issue is poor condenser heat dissipation, especially during summer traffic jams when the fan speed is insufficient, preventing the refrigerant temperature from dropping. Evaporator icing is also a hidden culprit; the air conditioning performance usually recovers during defrosting. Loose connections in the air conditioning control module are also common, often caused by water ingress during car washing leading to poor contact. Last time, a car had a loose fuse connection, causing the air conditioning to fail after half an hour of operation. I recommend first checking refrigerant pressure and pipeline temperatures—these basic diagnostics can quickly pinpoint the issue, saving unnecessary expenses on part replacements.

[MacKate]

I think this might be related to my car usage habits. For example, not changing the air conditioning filter for a long time can block half of the air ducts, causing the cold air to come and go intermittently. Also, improper settings of the automatic air conditioning system can trigger self-protection when the temperature difference between inside and outside exceeds 15 degrees. Once I tried lowering the fan speed, and the air conditioning worked stably. Blocked radiator grilles with willow catkins can also cause this issue – last month after cleaning them, the situation improved immediately. Additionally, pay attention to whether the compressor belt is slipping; if it's loose, the tensioner pulley needs adjustment. Aging and refrigerant leaks at air conditioning pipe joints can be very subtle and require fluorescent dye detection. During every maintenance session, remember to ask the technician to check the air conditioning's high and low pressures – prevention is much cheaper than repairs.