What are the symptoms of a faulty car expansion valve?
2 Answers
Here are the symptoms that may appear when a car expansion valve fails: 1. If the cause is blockage: Using a pressure gauge will reveal excessively high high pressure and excessively low low pressure. 2. If the cause is excessive opening: It will result in relatively low high pressure and relatively high low pressure. Below is relevant information about a faulty car expansion valve: The working state of the expansion valve should be to change the opening degree in real time according to the change of the evaporator load to control the flow. Due to the hysteresis in heat transfer of the temperature sensed by the temperature sensing package, the response of the expansion valve is always half a beat slow. The quality of the expansion valve is reflected in the amplitude of the fluctuation - the larger the amplitude, the slower the valve response and the worse the quality.
Last time my car's AC had issues, it was clearly the expansion valve failing! In the middle of summer, the AC would blow cold air one moment and hot air the next, like it was playing games. Can you believe the center vent on the dashboard could frost over? The low-pressure pipe felt freezing cold, covered in frost like an ice pop. Even worse, the AC compressor was super loud, constantly cycling on and off with jarring clicks that made your skin crawl. There was also a strong musty sour smell inside the car. Changing the cabin air filter didn't help—it turned out the expansion valve was clogged during inspection, messing up all the refrigerant flow. Had to replace the whole unit, cost nearly a thousand. Suggest checking this first if your AC acts up.
