What Are the Causes of Engine Idling Noise?
4 Answers
Excessive clearance, engine misfire, and engine knocking are all causes of abnormal noise during engine idling. The details are as follows: 1. Abnormal noise caused by excessive clearance. Clearance is a critical factor in automotive assembly quality. When lubrication, temperature, load, and speed are constant, the noise becomes more noticeable as the clearance increases. Some engine components may produce noise due to wear-induced excessive clearance. 2. Engine misfire noise. Engine misfire mainly refers to one or more cylinders not functioning properly, manifested as intermittent exhaust gas flow and severe shaking of the exhaust pipe, accompanied by clear "popping" or thumping sounds from the engine.
With years of experience in car repair, I've encountered many cases of strange noises during engine idling. The most common issue is loose or aged belts, which produce squealing or rattling sounds, especially in older vehicles. If the water pump bearings are worn out, they can also create a continuous tapping noise, and if not repaired promptly, the engine temperature can rise easily. Additionally, when the engine oil is too thin or insufficient, increased engine friction can lead to metal scraping sounds. Don't overlook spark plug problems either; poor ignition can cause the engine to hum and shake. I recommend car owners regularly check the belt tension and oil condition, as a small adjustment can prevent major troubles. When you hear unusual noises while parked, don't rush to drive off. Try turning off the air conditioning or fan to rule out whether auxiliary components are the culprits.
When I first started driving, the engine made a ticking sound when stopping at red lights, which really worried me. After researching, I found it might be due to excessive valve clearance or leaks in the exhaust system, with hissing sounds like wind. Some netizens also suggested it could be caused by incorrect oil grade leading to insufficient lubrication and friction. I tried checking the dipstick myself and felt slightly relieved when the oil color looked normal. For beginners encountering this situation, start with simple checks: park the car, open the hood to listen for the source direction, and avoid driving hard to prevent more serious damage. Developing the habit of checking fluid conditions during each maintenance can help solve engine noise issues early, preventing travel delays.
As an automotive enthusiast, I've found that most idle noises stem from minor issues, such as the scraping sound of a slipping belt or the clicking noise from a loose chain. These problems can worsen due to daily vibrations, and if left unattended, they may cause collateral damage to the water pump or generator system. The key lies in prevention: using the appropriate oil grade to control friction noise; regularly cleaning carbon deposits to prevent increased valve clearance. By adhering to routine maintenance, such as inspections every 3,000 to 5,000 kilometers, the engine can operate quietly, enhancing the driving experience.
