What Causes the Abnormal Noise During Cold Start?
4 Answers
The abnormal noise during cold start is usually caused by the loss of lubrication inside the starter's gears, leading to stiffness and jamming, which affects the timely return of the gears. Here are the relevant details: 1. When starting the engine, the starter motor rotates to drive the flywheel, thereby starting the engine. At this point, the engine's speed is driven by the starter, so the engine speed is lower than that of the starter. Once the engine starts and its speed exceeds that of the starter, manually turning off the ignition switch cuts the power, shutting down the starter. 2. Due to excessive dirt inside the starter and ineffective lubrication, the flywheel engine forcibly drives the starter to operate at its own speed. Since there is a speed difference between the two, this causes the abnormal noise heard from the starter. The noise only stops when the starter reaches the same temperature as the engine. However, in severe cases, the noise occurs every time the engine is started. To eliminate this noise, the starter must be cleaned and maintained or replaced.
Hearing squeaking or chirping noises during a cold start is really annoying, and it's mostly due to loose or aged belts. When the engine oil hasn't warmed up in cold weather, the belt tension isn't sufficient, making the friction particularly noticeable. The most common culprits are the alternator belt or fan belt—these tend to make noise in low temperatures as the rubber hardens. Chain issues are also not uncommon, especially in older cars, where gaps widen during cooling, resulting in rattling sounds. Piston rings may also produce noise from friction before the metal expands with heat. When I encounter this problem, I check the belts for cracks or wear. If they're loose, I adjust the tensioner myself or replace the belt. Don’t underestimate it—ignoring it might make the issue seem better in summer, but the noise worsens in winter, eventually damaging components and costing more to repair. Regular maintenance can prevent this, such as switching to synthetic oil before winter for better lubrication. Take your car to a specialized shop for a check-up—safety first, peace of mind guaranteed.
Strange noises when starting the car in the morning are often caused by belt issues. Cold engine oil is thick and provides poor lubrication, causing the alternator belt or fan belt to squeak if insufficiently tensioned. If the chain is worn or has foreign objects, it's quite common to hear clicking noises due to larger gaps at low temperatures. I've experienced this car's fuel pump making a whooshing sound during cold starts, caused by the low temperature of the fuel injection system. The solution is simple: try cleaning oil stains and carbon deposits on the belt pulley, and replace it with a high-performance belt if necessary. Identify the source of the noise—front-end sounds may indicate belt problems, while side clicking could point to chain issues. The problem may ease in summer, but inspect and address it early in winter for a quieter and smoother drive. Don't delay fixing it to avoid the hassle of a broken belt stranding you on the road. Develop the habit of warming up the car for a minute or two to aid lubrication—it's practical and convenient.
The noise from a cold start is really scary. For cost-conscious owners like me, experience suggests it's mostly due to aging belts or chain issues. In cold weather, when the lubricant hasn't circulated, squeaky sounds from loose belts are common. Friction from piston rings or large valve clearances becomes more noticeable in sub-zero temperatures. This isn't a major fault, but ignoring it can lead to engine damage, increased fuel consumption, and risks. I took it straight to the repair shop for a check-up; they fixed it by replacing the belt or adjusting the tensioner. Regular oil changes and maintenance, along with winter preparations, save money and ensure safety.
