What Causes Engine Abnormal Noise During Cold Start?
2 Answers
The causes of engine abnormal noise during cold start are: 1. Low oil pressure or wear in hydraulic lifters allowing air to enter; 2. Wear in valve rocker arms resulting in excessive valve clearance; 3. Throttle valve contamination due to accumulated sludge and carbon deposits; 4. Operational noise from carbon canister solenoid valve; 5. Malfunctioning fuel tank vent valve; 6. Fluid impact inside the recirculation pump; 7. Partial blockage in the fuel filter. Engine maintenance methods include: 1. Using high-quality engine oil; 2. Using qualified coolant; 3. Regularly cleaning radiator scale; 4. Periodic carbon deposit removal; 5. Timely replacement of three automotive filters; 6. Maintaining appropriate engine RPM.
Every time I start my car in the morning, the engine always makes a strange noise, especially on cold days. Common causes of abnormal noises include engine oil being too thick, poor fluidity when cold, and certain parts not being fully lubricated; it could also be due to aging or loose belts, causing squeaking; valve mechanisms like hydraulic lifters not working smoothly in low temperatures; or exhaust system leaks, producing popping or hissing sounds. These can all create noises that make people think there’s a major issue with the car. With years of experience in car repair, I’ve found that such problems should be addressed early. Otherwise, long-term neglect could worsen the situation—for example, belts snapping or internal engine wear, leading to increased fuel consumption and reduced horsepower, which isn’t worth the risk. I recommend first checking if the engine oil is expired or of an unsuitable grade, opting for a lower viscosity type in winter. Inspect belts visually for cracks and test their tension by hand. If anything seems off, visit a repair shop promptly—don’t skimp on safety. Regular maintenance, like seasonal oil changes, can prevent such issues and keep your car running smoothly.
