What causes severe shaking when the car fan is running?
3 Answers
If the shaking only occurs when the fan is running, the fault should be in the cooling fan system. Additionally, there are several other possible causes: 1. Check if there are any warning lights on the dashboard: If the engine warning light is on, it may indicate not only a fan malfunction but also potential engine issues. The vehicle should be taken to an authorized 4S dealership for professional diagnosis and repair. 2. Worn fan drive motor: Inspect the fan drive motor. Excessive clearance, severe wear, or shaft jamming in the motor can cause fan wobbling during operation, leading to vehicle vibration.
The fan suddenly started shaking violently, which I also encountered recently—the entire hood was vibrating. After checking, it's usually due to unbalanced or loose fan blades—possibly from dust buildup or something stuck, like small stones or leaves, causing wobbling during rotation. Another reason could be loose fan mounting screws, where even slight looseness amplifies into shaking at high speeds. For belt-driven fans, worn or overly loose belts can also cause this, along with engine vibration. I tried checking myself: after parking and turning off the engine, I felt the blades for any debris and gently tightened related parts with a screwdriver. But don’t force it—easy to damage. If unsure, head to a professional shop quickly; a thrown fan can cause worse damage. During regular maintenance, ask the technician to check the fan assembly’s balance and tightness—it prevents most issues.
Last time I drove, the fan was shaking like an earthquake—turned out the fan blades were caked with mud, causing imbalance at high speeds. Rusty bearings are another common culprit; insufficient lubrication leads to increased friction, resulting in severe shaking and potential noise. If the fan bracket screws are aged or loose, they directly amplify the wobble. Another incident involved the belt system—a loose belt slipping and destabilizing the fan. My usual approach is to pull over, pop the hood, and inspect the blades for cleanliness, cracks, or deformities. I’ll tighten the screws with basic tools, but carefully to avoid over-torquing. Ignoring this issue risks blade detachment, damaging other engine components and doubling repair costs. During regular car washes, I wipe down the fan area to minimize dirt buildup, preventing most shaking scenarios.
