What Causes the Air Conditioner to Make Loud Noises When Turned On in a Car?
2 Answers
There are several reasons why the engine noise becomes louder when the car's air conditioner is turned on: Air conditioning pump noise: If there is an issue with either the electromagnetic clutch or the bearings inside the air conditioning pump, it can cause the pump to produce abnormal noises. Throttle valve clogging or sticking: If the throttle valve has carbon buildup or is sticking, it can lead to engine shaking and abnormal noises. Reasons for no air flow from the car's air conditioner: Blower fan malfunction: The car's blower fan is a crucial component for air flow from the air conditioner. If the air conditioning compressor fails during operation, the air conditioner will not produce air. Clogged air filter: The air filter is a significant and common reason for no air flow from the air conditioner. During operation, the car's air conditioner can accumulate many impurities from the air. Control system failure: This could be due to issues with the air vent, air conditioning computer, or control switch. Control system switches generally do not fail, and it is recommended that the owner visit a 4S shop for inspection to simplify the troubleshooting process.
Back when I drove an older car, I also encountered the issue of loud AC noise. I later realized the sound mainly came from the blower area. If the blower bearings lack lubrication or accumulate dust, they can produce a tractor-like humming noise when spinning. Also, check if the air volume knob is set to the maximum setting—the highest fan speed naturally generates louder noise. Last time I removed the cabin air filter and found it clogged with willow catkins, completely blocking the air ducts, forcing the blower to work extra hard to push air through. These issues can be checked yourself: after turning off the engine, open the hood and listen for abnormal noises near the blower location; clearing leaves and debris around the AC air intake also helps. If the fan blades are warped or the bearings are completely worn out, you’ll need a professional mechanic to replace the parts.
