What is the reason for high low pressure and low high pressure in the Volkswagen Magotan's air conditioning?

[KingstonFitz]

The reason for high low pressure and low high pressure in the Volkswagen Magotan's air conditioning is due to dust, mud, willow catkins, and other debris trapped in the gaps between the condenser and the radiator, which affects water temperature and air conditioning cooling performance. Introduction to Car Air Conditioning: The car air conditioning device (air-conditioning-device), referred to as car air conditioning, is used to adjust and control the temperature, humidity, air cleanliness, and airflow inside the car cabin to an optimal state. It provides a comfortable riding environment for passengers, reducing travel fatigue, and creates good working conditions for the driver, playing an important role in ensuring safe driving as a ventilation device. Air Conditioning Layout: The layout of different types of air conditioning systems varies. Currently, integrated heating and cooling air conditioning systems are widely used in sedans. The layout involves assembling the evaporator, heater core, centrifugal blower, and control mechanism together, known as the air conditioning unit assembly.

[MollyMarie]

The Magotan I repaired the other day had exactly the same issue - the low-pressure pipe felt icy cold but the gauge showed abnormally high pressure, while the high-pressure pipe temperature was normal but couldn't build up proper pressure. Essentially, it's a refrigerant circulation problem: either insufficient refrigerant or air contamination weakening heat absorption, causing liquid refrigerant accumulation at the low side; or worn compressor piston rings compromising sealing and reducing pumping efficiency, preventing high-pressure buildup. Another possibility is faulty condenser fan control logic causing poor heat dissipation that drags down high pressure. Remember to first measure the actual temperature difference between high and low pressure pipes - this reveals more than just reading pressure gauges alone.

[DavidDella]

In my opinion, the focus should be on checking the compressor, as the inability to build up high pressure is mostly due to its poor working condition. Internal leakage may cause insufficient pumping capacity, failing to compress the gas properly, resulting in naturally low high pressure; while the high low pressure is often due to the compressor's insufficient suction force, leading to incomplete gas return at the low-pressure end. It's like a person running out of breath while running, inhaling less and exhaling inadequately. Additionally, if the receiver-drier is clogged, similar symptoms may occur. If the temperature difference between the two ends of the tank exceeds 10 degrees, it's highly likely to be clogged. By the way, under such faulty conditions, the air conditioning may intermittently cool or even blow hot air.

[DiCorey]

In 90% of cases, the contradictory phenomenon of low pressure being high while high pressure is low is caused by a faulty expansion valve. I've seen several Magotans suffer from stuck expansion valve needle valves: when it should close, it doesn't seal properly, allowing excessive liquid refrigerant to accumulate in the low-pressure line, causing falsely high pressure; when it should open, the opening is insufficient, resulting in inadequate flow and pressure on the high-pressure side. If you feel the low-pressure line and it's extremely cold with frost formation, that's basically conclusive evidence. By the way, during this time, the sound of the compressor idling will be unusually loud, with a particularly dull humming noise.