What are the causes of the rattling noise in diesel engine?
2 Answers
Diesel engine rattling noises can be attributed to the following aspects: 1. Piston top noise: Small washers, screws, etc., fall into the cylinder through the intake pipe or the hole for installing the fuel injector, hitting the piston top when the piston moves near the top dead center. Severe wear or damage to the connecting rod bearing causes excessive clearance, leading to the piston hitting the valve when moving near the top dead center, and in severe cases, even impacting the cylinder head. 2. Valve noise: The knocking of the rocker arm on the valve stem end increases, resulting in a crisp knocking sound. 3. Cylinder gasket noise: Small bubbles appear at the edge of the cylinder gasket, producing a gas leakage sound that starts small and sharp, with a tendency to grow louder. 4. Cylinder noise: Causes of cylinder noise include severe wear between the piston and cylinder, excessive clearance between the piston and cylinder wall, piston deformation, excessive tightness between the piston pin and connecting rod bushing, and connecting rod deformation.
I've encountered the issue of a diesel engine making a ticking noise several times. It could be due to slight dripping or clogging of the fuel injectors, causing uneven fuel injection and producing a metallic clashing sound. Another possible cause is wear or loosening of the timing chain or gears, resulting in a ticking noise during operation. Excessive or improperly adjusted valve clearance in the engine can also produce a crisp sound during opening and closing. Additionally, problems with the lubrication system, such as oil being too thin or insufficient, can increase friction between components. Loose connecting rod bearings are another common cause. It's recommended to immediately check the oil condition and ensure normal oil pressure. If the problem persists, it's best to visit a repair shop for professional testing of the fuel injectors and timing system to prevent engine damage.
