What Causes Engine Shaking When Shutting Off?
2 Answers
Engine shaking when shutting off may be caused by the following reasons: 1. Excessive carbon deposits: Too much carbon buildup can lead to pre-ignition and detonation, shortening the engine's lifespan and significantly reducing its power and fuel efficiency. 2. Carbon deposits and gumming on valve guides and valve stems: This accelerates wear between the valve stem and guide, and may even cause the valve stem to stick in the guide, resulting in valve sticking issues. 3. Carbon deposits in piston ring grooves: This reduces or eliminates the side and back clearance of piston rings, causing them to lose elasticity and potentially leading to cylinder scoring; Carbon deposits on fuel injectors can cause uneven fuel injection among cylinders, resulting in engine shaking or hesitation.
I've driven quite a few cars and experienced engine shaking upon shutdown several times. The most common causes are issues with the spark plugs or ignition coils. After a few years of use, spark plugs tend to wear out and produce weaker sparks, leading to engine shaking during shutdown. Similarly, if the ignition coil is aging and the voltage becomes unstable, it can cause the same problem. Additionally, excessive carbon buildup inside the engine, especially around the throttle body and fuel injectors, can affect the fuel-air mixture, causing the car to shake unevenly when turning off. I recommend regularly checking the spark plugs and replacing them every 20,000 kilometers, as well as cleaning the carbon deposits to prevent this shaking. Using low-quality gasoline right after refueling can also trigger the issue, so it's important to use good fuel. Also, if the idle valve gets stuck, the car may tremble when parking. This small component is prone to dust accumulation, so a simple cleaning during routine maintenance will do. In short, timely inspections and maintenance are crucial to avoid engine damage.
