What Are the Causes of Diesel Engine Idling Shaking?

1 Answers
ParkerRose
07/24/25 4:35pm
Common causes of diesel engine idling shaking: 1. A certain cylinder's fuel injector nozzle is stuck or has poor atomization, causing the cylinder to not work or work poorly (blue-white smoke will be emitted from the exhaust). This can be checked using the cylinder cut-off method. 2. Uneven idle fuel supply from the fuel injection pump, leading to uneven operation of cylinders at idle. 3. Improper idle adjustment (too low RPM), which can be resolved by adjusting the idle fuel supply screw. 4. Incorrect valve clearance (due to loose adjustment screws, abnormal wear, or abnormal wear of valve pushrods), causing the cylinder to not work or work poorly. This can be fixed by adjusting the valve clearance. 5. Poor valve sealing, resulting in poor operation. 6. Engine overheating or insufficient oil (causing poor lubrication), making it difficult for engine components to operate. Below is additional information on engine idling shaking: Severe engine carbon buildup is the most common cause of car shaking. When there is excessive carbon buildup inside the engine, the gasoline sprayed by the cold start injector is largely absorbed by the carbon deposits, leading to an overly lean air-fuel mixture during cold starts and making it difficult to start. In this situation, the car will only start easily once the carbon deposits have absorbed enough gasoline. After starting, the gasoline adsorbed on the carbon deposits is sucked into the cylinder by the engine's vacuum and burned, making the air-fuel mixture too rich. This causes the engine's combustible mixture to fluctuate between lean and rich, resulting in idling shaking after a cold start. The lower the temperature, the more fuel is needed for a cold start, and the presence of carbon deposits will significantly affect the success of the cold start. The solution is to clean the fuel system and check if the idle control valve has carbon buildup, which should also be cleaned.
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