What Causes the Sizzling Sound During Cold Start of a Car?
2 Answers
There are mainly three reasons for abnormal sounds during cold start of a car: 1. Poor combustion: When the car does not provide sufficient power, it may produce abnormal sounds. 2. Low ignition energy leading to abnormal sounds: The first issue a car faces during cold start is low temperature. The temperature inside the engine is insufficient, and both the fuel and lubricating oil are not warm enough. Therefore, more fuel should be injected during cold start to meet the power requirements. 3. Poor fuel atomization at low temperatures: Fuel requires higher ignition energy. After prolonged use, the ignition gap of the spark plug increases, leading to a decrease in ignition energy, which affects the power performance and causes the car to produce abnormal sounds.
A hissing sound during cold starts is something I've encountered many times as a veteran driver with over a decade of experience. The common causes are a loose or aged alternator belt or air conditioning belt. When the engine first starts, the cold belt hardens and creates friction against the pulleys, resulting in a hissing noise. If ignored, the belt may snap, causing the alternator to stop working or the battery to drain quickly, which can lead to a dangerous breakdown on the road. For a quick self-check: pop the hood and observe if the belt slips during a cold start. If you notice cracks, replace it immediately. Other possibilities include worn bearings in the tensioner pulley, which produce a sharper sound and require professional adjustment. Remember to have a technician inspect the belt condition during regular maintenance—typically replaced every 50,000 kilometers or so. Don't skimp on this small expense; safety comes first.