What causes the squeaking sound when starting a car?
2 Answers
When a car makes a squeaking sound immediately upon starting, it is usually due to a loose or abnormal timing belt. More relevant information is as follows: 1. When the engine is running at high temperatures, incorrect matching and installation of the timing belt tensioner can affect the service life of the timing belt. During the starting process, whether at low or normal temperatures, if a squeaking sound occurs, the timing belt should be replaced promptly. The timing belt is a crucial component of the engine system, ensuring the proper timing of intake and exhaust by connecting to the crankshaft and maintaining a specific transmission ratio, thereby guaranteeing the engine's normal operation. 2. The reason cars use belts for transmission instead of gears is that belts produce less noise and provide precise transmission.
Every time I start the car, there's a squeaking sound, and I suspect it might be the starter motor or the belt causing the issue. When the starter motor rotates, if its engagement gear is slightly worn or lacks sufficient lubrication, it can produce a sharp friction noise, especially noticeable during cold starts. Similarly, if the belt system is aged, cracked, or loose, it can also squeak during operation, particularly the belt for the air conditioning compressor. This sound is usually brief, but if ignored, it could lead to starting failure or belt breakage, affecting engine performance. I recommend regularly checking the belt's tension and wear condition, applying specialized lubricant or replacing parts when necessary. This problem tends to occur more often after the car has been parked for a long time before starting, so keeping the engine compartment clean can also reduce dust buildup that might cause unusual noises.
