What Causes Loud Noise from Car Radiator Fan?

[EverettAnn]

It may be related to the fan belt or the balance of the fan blades, or possibly due to a dirty radiator causing poor heat dissipation, which affects the air intake volume. This leads to the electric fan increasing its rotation speed, resulting in increased wind noise. This issue does not affect daily use. It is recommended to clean the radiator and fan blades, and check if the fan's mounting screws are loose. Below is an introduction to the electric fan: 1. Composition: The electric fan is designed to prevent the engine coolant temperature from becoming too high. It consists of a sensor, electric fan, chip, etc. 2. Function: When the coolant temperature generally exceeds 90 degrees, the sensor activates, and the electric fan turns on to lower the coolant temperature. In winter, when temperatures are lower and the coolant temperature is also lower, the electric fan usually does not operate, protecting the engine from working in excessively cold or hot conditions.

[AlexanderMarie]

I think there are usually several situations when the radiator fan noise is loud. I encountered similar problems when driving older cars before. The most common issue is deformed fan blades, where even a slight touch against the protective mesh can produce a harsh noise, especially noticeable when the AC is on during summer. Bearing wear is another persistent problem - lack of lubrication after prolonged use causes continuous humming noises. Additionally, worn-out brushes inside the fan motor can cause unstable current flow and increased noise. I suggest paying attention to the sound pattern: if it's a continuous humming, it's likely bearing issues; if it's a clicking sound, it's probably deformed blades. This problem needs timely attention - last year my friend delayed repairs until the fan completely failed on the road, causing engine overheating and costing thousands in additional repair fees.

[IvanAnn]

Recently, my car also had the issue of loud fan noise. After some research, I found several common causes: First, the radiator was clogged with willow catkins, forcing the fan to spin wildly to cool down, resulting in loud noise; Second, loose mounting screws caused the fan to wobble and produce a rumbling sound when rotating; Third, the fan control module might be faulty, keeping the fan running at high speed continuously. Last week, I tried cleaning the radiator with a high-pressure water gun, and the effect was quite noticeable. If you're handy, you can check if the fan bracket has any cracks, but when it comes to electrical circuits, it's safer to consult a professional technician, as the fan is connected to the car's power system. Regularly cleaning the radiator and condenser can effectively prevent this issue—I usually rinse them with a water gun every two months.

[BethanyDella]

I've encountered many fan noise issues during car repairs. The most common is damaged fan bearings, which have noticeable looseness when shaken; next is deformed fan blades, often seen in vehicles after hitting the chassis; and there's motor rotor scraping, where friction noises can be heard. It's recommended to focus on checking these three items: shake the fan by hand to check bearing clearance; observe if the blade rotation path is smooth; use a stethoscope to diagnose internal motor noise. Additionally, modifying lights can increase electrical load, causing the fan to start frequently. Recently, an old Sagitar I repaired developed noise after light modification, and it became quiet after restoring the original circuit. Cooling system issues shouldn't be delayed, as they can easily lead to high-temperature stalling.