What is the ticking sound in a diesel engine?
2 Answers
Car engine ticking noise is a normal phenomenon during cold starts or could be related to oil issues. Below are the reasons for car engine ticking noise: 1. Reason one: During a cold start, the engine sound is slightly louder than when the engine is warm. As long as the sound is uniform and smooth, not harsh, it is generally not a problem. This is because when the engine is cold, the gap between the cylinder wall and the piston has not reached the optimal size, and the oil lubrication is not sufficient. Typically, once the engine block temperature reaches around 95 degrees, the sound will return to normal; 2. Reason two: Poor-quality oil or not changing the oil for a long time, or lack of oil, can easily increase friction between the valves and guides, as well as hydraulic lifters, making various sounds in the engine louder. Therefore, it is necessary to refuel at regular gas stations.
I'm a seasoned diesel engine mechanic, and the 'clattering' sound is quite common in diesel engines, but it depends on the situation. Normally, it's the noise from the fuel injectors working—diesel combustion has high pressure, creating a metallic knocking sound during injection, especially during cold starts or low-speed operation. If the sound becomes unusually loud or changes rhythm, there might be an issue: the most common causes are uneven pressure due to aging or clogged fuel injectors, or excessive valve clearance needing adjustment. Worn connecting rod bearings can also produce similar noises. I once repaired a vehicle where the connecting rod was loose, causing strange sounds, and it ended up requiring an expensive engine overhaul. The best prevention is regular inspection of the fuel injection system and bearing conditions, along with using high-quality diesel to reduce impurity buildup.
