Why is there a clunking sound when the car starts?

[OJason]

If there is a clunking sound when the car starts, it may be due to clutch failure, transmission failure, lower arm failure, or inner CV joint wear. It is best to go to a local 4S shop or professional repair shop for inspection and repair. Clutch: The clutch is located in the flywheel housing between the engine and the transmission. The clutch assembly is fixed to the rear plane of the flywheel with screws, and the output shaft of the clutch is the input shaft of the transmission. During driving, the driver can press or release the clutch pedal as needed to temporarily separate and gradually engage the engine and the transmission, thereby cutting off or transmitting the power from the engine to the transmission. Notes: Before installation, the clutch must be cleaned thoroughly to remove anti-rust grease and debris. The clutch can be installed coaxially or on separate shafts. The axial direction must be fixed, and neither the driving part nor the driven part is allowed to have axial movement. When installed on separate shafts, the coaxiality between the driving part and the driven part shaft should not exceed 0.1mm.

[ReidDella]

I've been driving for many years, and the clunking noise during startup is most likely related to the suspension, such as wear and looseness in the lower control arm ball joint or excessive play in the tie rod. Aging and deformation of the engine mounts can also cause noise when the body shakes. Additionally, loose exhaust pipe hangers can result in collision sounds during rapid acceleration. Neglecting these parts for a long time may lead to faster deterioration and even affect driving safety. I always recommend getting the chassis checked by a professional shop as soon as possible after driving—they can accurately identify the issue and replace the faulty parts. Addressing it early saves money and hassle; don't delay.

[XavierMarie]

From a technical perspective, the initial clunking sound often originates from the drivetrain. When the transmission mount is deformed or loose, it can collide with the chassis under strong starting impact. Loose engine mounting bolts or worn suspension bushings will amplify the gaps and generate noise. I've personally researched this issue—high-temperature environments accelerate component aging. It's essential to rule out brake pad sticking or abnormal wheel hub bearings. A mechanic can use tools to measure the gaps and fix it, which is simple and effective.

[VonAvery]

I'm worried my car might be broken when I hear a clunking sound during startup. It could be loose suspension components or the brake discs not fully releasing, causing a dragging noise. Safety first—I immediately drive to the repair shop every time I hear it. They can quickly diagnose the issue and replace any worn parts. Don't ignore this sound; prolonged neglect could damage the chassis and cost more to fix. After repairs, the startup became much smoother.