Reasons for Low Intake Pressure

[DeHazel]

Reasons for low intake pressure may include blockages in the refrigerant system's liquid supply pipe, expansion valve, or filter, insufficient refrigerant charge in the system, excessively long evaporator pipelines, etc. Blockages: Blockages in the refrigerant system's liquid supply pipe, expansion valve, or filter, or insufficient opening, malfunctioning float valve, low ammonia liquid circulation in the system, insufficient height difference or small pipe diameter in the intermediate cooler's liquid supply, can all lead to excessively low compressor suction pressure. Insufficient Refrigerant Charge: Insufficient refrigerant charge or liquid supply in the system, or improper adjustment of the throttle valve, can result in low compressor suction pressure. Excessively Long Evaporator Pipelines: If the evaporator pipelines are too long or if the design of the parallel suction header for multiple compressors is improper, it can also cause low compressor suction pressure. Excessive Oil Content in Freon System: Excessive oil content in Freon systems, which easily dissolves oil, can lower the suction pressure. Thick Frost or Oil Buildup in Evaporator: Thick frost or oil buildup on the inner walls of the warehouse evaporator increases thermal resistance, leading to reduced suction pressure.

[ElliottRose]

There can be various reasons for low intake pressure. A common one is a clogged air filter, where dust accumulation restricts airflow, leading to insufficient intake pressure. Leaks in the intake manifold or pipes, such as from aging gaskets or cracked tubes, are also problematic. Faulty sensors like the MAP or MAF can provide incorrect readings, affecting pressure signals. If the turbocharger malfunctions, it can also cause a drop in pressure. These issues may result in reduced engine power, increased fuel consumption, or even stalling. I recommend regularly checking the air filter to ensure it's clean. If you notice poor acceleration, promptly visit a professional shop for diagnosis and repair to avoid engine damage.

[VanElla]

Low intake pressure is mainly caused by restricted airflow or system leaks. A dirty air filter is one of the common reasons; when clogged, air cannot enter, naturally resulting in low pressure. Cracks in the pipes or manifold can also cause air leaks, reducing pressure. Sensor failures, such as an inaccurate MAP sensor, can lead to ECU misjudgment, affecting overall operation. In modified cars, these issues are more likely to occur, but you can perform a preliminary check yourself: listen for any hissing sounds indicating air leaks or check if the air filter is clogged with dust. This can lead to poor engine performance, feeling sluggish during acceleration, and early maintenance can prevent further issues.

[MacDallas]

Possible causes of low intake pressure include clogged filters, system leaks, or sensor malfunctions. Blockages prevent air from entering smoothly, resulting in insufficient pressure; leaks, such as damaged manifold gaskets, allow air to escape; sensor issues cause the control unit to misread. This reduces engine efficiency, increases the risk of stalling while driving, and poses significant safety hazards. It is best to address the issue promptly and perform regular maintenance while driving to minimize risks.