Why Does a New Car Make a Clicking Noise When Starting?

[StNorah]

If a new car makes a clicking noise when starting, it could be due to clutch failure, transmission failure, lower control arm failure, connecting rod bearing failure, or inner CV joint wear. The owner should promptly visit a local 4S shop or professional repair shop for inspection and repair. Types of car noises: 1. Normal noises: These include normal vibration sounds from various system components (such as engine surface noise), gear impact sounds during shifting, intake and exhaust sounds from gas-operated systems, and gear meshing noises. 2. Abnormal noises: Abnormal noises can be categorized into minor noises, moderate noises, and severe noises based on their impact on the car's performance. Minor noises, such as sparking sounds from high-voltage electricity leakage or slight looseness in rolling bearings, are less concerning. Severe noises, such as loud sounds from crankshaft bearings or connecting rod bearings accompanied by a drop in oil pressure, significant gear impact sounds in the transmission, or strong vibrations from the differential, can seriously affect the car and may cause or have already caused severe damage to components.

[OCassandra]

Last time I helped a friend inspect a new car, I encountered this issue as well. The clunking sound mostly comes from the suspension system. During transportation, suspension components are secured, and some bushings might still be tight when the car is first driven. The initial torque release from the engine causes slight frame deformation, shifting the stress points on the suspension, which can lead to brief metallic noises at the joints. Additionally, the driveshaft universal joints are tightly assembled at the factory, and such sounds are common during the break-in period. It's recommended to drive for 500 km first and observe. If there are still noticeable metallic clunking sounds after 1,000 km, check the torque of the chassis bolts and the lower arm bushings. Remember to avoid speed bumps during testing—tilting over bumps makes the sound most apparent.

[VanJoshua]

This kind of abnormal noise is quite annoying, especially for a brand-new car. I had a car that did the same thing, and later found out it was caused by the brake pad gap. The protective oil on the new brake discs wasn't completely removed, which would absorb brake dust after parking, causing a slight displacement between the brake pads and calipers when starting the car cold, resulting in a clunking sound. Additionally, excessive preload on the steering rack can transmit vibrations to the pedal. Focus on checking these two areas: try not to pull the handbrake too tight overnight and lightly press the brake when starting; or repeatedly turn the steering wheel to full lock to test. In fact, many luxury brands have factory settings that are on the tighter side, and the noise usually disappears after two weeks of driving. However, clunking sounds from the ABS pump should be taken seriously.

[MacKendra]

New car startup noises can be divided into high-frequency and low-frequency types. The dull low-frequency noise indicates the subframe bushings haven't fully settled, like new shoes pinching your feet; the crisp high-frequency sound may suggest insufficient lubrication of the driveshaft splines. Last time when accompanying my neighbor to the dealership, the technician used a stethoscope to diagnose it as engine guard resonance - caused by bolt shim vibration due to dimensional tolerances in the aluminum guard's mounting holes. Here's a trick: rev the engine in neutral to locate the noise source while having a friend feel the suspension springs, as sticky spring rebound can produce similar sounds. Don't rush to disassemble the car - most noises disappear after break-in, but persistent metallic knocking requires immediate repair.

[DeAdeline]

The knocking noise should be analyzed based on whether the engine is cold or warm. If it's more noticeable when the engine is cold, it's usually caused by the displacement and collision of rubber components due to thermal expansion and contraction. The most typical case I've seen is when the ball joint of the stabilizer bar link is too tight, making a clicking sound like a dislocated joint during torque changes at startup. There's also the impact sound from the starter gear engagement when the auto start-stop system is active. It's recommended to turn off the start-stop system for three days or try starting slowly with the clutch partially engaged. For rear-wheel-drive vehicles, pay attention to the differential preload issue, while for front-wheel-drive vehicles, focus on inspecting the drive shafts. Even with assembly tolerances controlled within 0.2mm, new cars can still produce noises, but noises caused by leaking hydraulic bushings will become increasingly frequent.