What is the reason for abnormal noise when starting the car?

[LeRowan]

The reasons for abnormal noise when starting the car: 1. The sound of the timing chain; 2. Insufficient lubrication during cold start, resulting in friction noise from metal parts; 3. The sound produced by the slipping of the motor belt during cold start. Check the tightness of the motor belt and see if there is any aging; 4. Poor retraction of the starter; 5. The battery has issues, either it is undercharged or its lifespan has expired. For example, forgetting to turn off the headlights when parking or not turning off the car's electrical appliances, leading to undercharging. In such cases, the battery needs to be replaced. It is recommended to go to a 4S shop or a professional auto repair shop promptly for the technician to inspect and determine the problem before carrying out the appropriate repair.

[IanDella]

I've been driving for over a decade and have encountered several instances of abnormal noises during ignition, typically the sound of the starter gear slipping, which sounds like a 'click-click' noise. This could be due to gear wear or improper meshing, especially when the oil is thicker in cold weather, causing poor operation. Another common cause is aging and slack in the auxiliary belt, with a very noticeable squeaking sound. I've tried visually inspecting the belt for cracks myself, and if any are seen, I replace it immediately. Ignoring these issues can gradually worsen the wear, such as the starter completely failing and making the car unable to start, requiring towing to a repair shop and costing more money. It's recommended to first check the battery voltage; if it's normal, then focus on the starter and belt areas. Regular maintenance can significantly reduce the likelihood of these problems.

[StLilliana]

As a regular car owner, I occasionally heard strange noises when starting the car but didn’t pay much attention. Later, the sound became slightly louder, resembling a squeaky friction noise or a short clicking sound. After consulting a mechanic friend, I learned there could be multiple causes: it might be due to insufficient battery voltage causing the starter to struggle and make noise, or the belt could be loose from aging, slipping and producing noise. Cold weather makes it more likely to occur, but warming up the car for two minutes in the morning improves the situation significantly. Additionally, belt issues are more frequent in summer because high temperatures accelerate aging. Ignoring these problems can worsen the noise and even lead to a failed start, leaving you stranded. I’ve now developed a monthly inspection habit, checking for loose battery terminals. Addressing issues early saves money and hassle—don’t wait for a major breakdown.

[Rhett]

Ignition noises should never be ignored, as they come in two types: a brief clicking sound often indicates poor engagement of the starter gear, while a squealing noise usually points to belt or bearing wear. After experiencing this once, I now insist on prompt inspections because prolonged neglect can lead to more severe failures, such as belt breakage affecting the AC or steering system. Potential hazards include ignition failure in dangerous areas, especially at night or on highways. Quickly checking battery health is crucial—replace or recharge if voltage drops below 12V. Developing a warm-up habit helps reduce cold-start issues.