What Causes Slight Engine Idle Shaking with Normal Tachometer Reading?

[JasmineRose]

Engine slight idle shaking with normal tachometer reading is caused by engine carbon buildup and throttle valve malfunction. Excessive engine carbon deposits: If significant carbon accumulates in the engine over a short period, it can lead to increased fuel consumption, which is often caused by using substandard fuel. The solution is to add a certain amount of fuel system cleaner during refueling. If this proves ineffective, it indicates substantial carbon buildup inside the engine, requiring professional cleaning by technicians at a 4S shop or auto repair facility. Throttle valve malfunction: Hard faults refer to mechanical damage. The resistor part of the potentiometer is made by spraying a carbon film onto a polyester substrate - a relatively basic manufacturing process with limited wear resistance. Soft faults include contamination, misalignment, and similar issues.