What Are the Causes of Abnormal Noises When Starting a Car?
2 Answers
Abnormal noises when starting a car can be caused by factors such as excessively low engine temperature, thermal expansion of the car's three-way catalytic converter, transmission failure, or wear of the engine belt or chain. It is recommended to visit a 4S shop for maintenance and inspection to eliminate the fault. Causes of abnormal noises when starting a car: Excessively low engine temperature: During a cold start, the engine temperature is too low for normal operation, resulting in some abnormal noises. This is a normal phenomenon, and the noises will disappear once the engine temperature rises to normal levels. Thermal expansion of the car's three-way catalytic converter: If there are abnormal noises when the car is just started but they disappear after a while, this is caused by the thermal expansion of the three-way catalytic converter and is also a normal phenomenon that does not require attention. Transmission failure: One of the reasons for abnormal noises when starting a car is transmission failure, which causes internal gears to rub and produce noises. This situation is more complex and requires professional inspection at a repair shop or 4S shop. Wear of the engine belt or chain: If the engine belt or chain is worn, it can cause friction or idling noises when starting the vehicle. For safety reasons, it is best to directly replace the engine belt or chain in such cases.
My car also had that screeching noise when starting before, and later it was found to be a squeaking sound caused by a loose or aging belt slipping. Another common reason is issues with the starter, such as gear wear or poor retraction, which can cause a rattling noise at the moment of starting. Additionally, aging exhaust pipe gaskets leaking and causing a puffing sound during cold engine starts are also common. Broken engine mounts can also lead to vibration noises. I suggest you first listen to the location of the sound: belt noises are usually in the front compartment, while exhaust sounds are under the car. If it's a brief abnormal noise during cold starts, it might be normal, but if it persists, you should go to a repair shop. Small issues left unfixed could lead to starter failure or belt breakage, leaving you stranded.
