What Causes Abnormal Noise After a Cold Start?
1 Answers
Abnormal noise after a cold start can be attributed to the following reasons: 1. Aging of the generator belt. Made of rubber, the belt contracts in cold conditions due to thermal expansion and contraction. Combined with the elongation from daily rotation, this can cause the belt to slip during a cold start, producing noise. 2. Issues with the valve tappets. During a cold start, engine oil is pressurized from the oil pump through the engine oil passages to the valve tappets, which can result in louder startup noises. 3. Lack of lubrication inside the starter motor gears, leading to sticking and affecting timely gear retraction. 4. Malfunction of the carbon brushes inside the starter motor.