What Causes the Extremely Loud Noise When Starting a Lingdu Cold Engine?
2 Answers
Lingdu cold engine starting noise may be caused by intake noise generated by the engine intake system or abnormal wear of the engine's external belts or pulleys. Below is a detailed introduction to the reasons for the loud starting noise: 1. Winter reasons: In winter, the atomization conditions of gasoline are poor, especially for carburetor-equipped vehicles, which are generally difficult to start, and even after starting, they cannot immediately transition to normal operation. Therefore, during winter maintenance, it is necessary to clean and unclog all oil and air passages, check the working conditions of the throttle valve, choke valve, accelerator pump, and vacuum pump, and adjust them to the optimal state. At the same time, the idle fuel supply concentration should be appropriately adjusted to ensure normal idle operation in severe cold. 2. Spark plug reasons: For the electrical circuit, mainly check the platinum gap of the distributor and the electrode gap of the spark plug. The platinum contacts of the distributor should be clean and free from burns, with a contact surface of more than 70%, and the gap should be between 0.3 and 0.45 millimeters. For models with electronic ignition, the spark plug gap is generally between 0.6 and 0.7 millimeters. If the spark plug gap is too large, the engine is difficult to start when cold. If the gap is too small, the engine's output power decreases, fuel consumption increases, and exhaust emissions exceed standards.
In my career of car repair, I've encountered many cases of loud cold starts in the Lamando, mainly due to insufficient lubrication when the engine is cold, clogged oil passages, or low oil pressure. Issues like loose belts can also cause squeaking sounds, especially in low temperatures when material contraction increases friction. Chain tensioner failure is another common problem; it controls the movement of the timing chain, and when faulty, it produces a rumbling noise. Poor sealing in the exhaust system or carbon buildup in the catalytic converter can also cause abnormal sounds during startup due to restricted gas flow. It's advisable to check if the engine oil is expired, and switching to high-quality full synthetic oil can improve lubrication. The issue is more noticeable in winter but tends to improve after warming up the car for a few minutes. If the noise persists, it's best to have a professional shop inspect the tensioner or belt components. Don't ignore prolonged noise, as it can damage the engine and lead to costly repairs.
