What are the reasons for engine shaking at idle?
2 Answers
Engine shaking at idle is mainly caused by: 1. Unstable oil pressure. If the fuel pump's supply pressure is abnormal or the intake pressure sensor values are incorrect or malfunctioning, it can cause body shaking. Solution: Check oil pressure and replace components if necessary. 2. Severe engine carbon buildup. When there is excessive carbon buildup inside the engine, the gasoline sprayed by the cold start injector can be largely absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture during cold starts, making it difficult to start and causing the car to shake. Solution: Clean the fuel system and check if the idle control valve has carbon buildup that needs cleaning. 3. Ignition system issues. Poor performance of the ignition system or bad spark plug firing can also cause car shaking. Solution: Check if the spark plugs have excessive carbon buildup and replace them if necessary.
I've been driving for many years and often encounter car shaking at idle. I've summarized several common causes. The most common is ignition system issues, such as aging or worn spark plugs that fail to ignite properly, causing unstable engine operation and resulting in body vibration. Another cause is the fuel system; clogged fuel injectors or poor fuel line flow leading to insufficient fuel supply can also cause shaking. If the engine mounts are worn or cracked, their shock absorption deteriorates, making the car shake as if dancing. Carbon buildup is another persistent issue; carbon deposits on intake valves or pistons affect the air-fuel mixture ratio, making the car prone to shaking at idle. Once, my car shook severely, and after inspection, replacing the spark plugs and cleaning the fuel injectors solved the problem. I recommend regular maintenance, such as checking spark plugs every 20,000 kilometers, which can prevent many issues and even save some fuel costs.
