What causes slight shaking when the car is idling?

[LeAlexis]

The reasons for a car shaking during idle are as follows: 1. Intake system failure: Excessive carbon buildup in the throttle body and intake manifold, clogged air filter element, leaks in the intake pipe or EGR valve, faulty intake pressure sensor. 2. Fuel system failure: Fuel supply pressure issues, faulty fuel injectors. 3. Ignition system failure: Spark plugs not firing or weak spark energy, faulty ignition module or ignition coil, malfunctioning sensors or ignition control circuit. 4. Electronic control system failure: Internal circuit damage or poor contact in the electronic control system. 5. Mechanical structure failure: Damaged or weakened piston rings, carbon buildup in piston ring grooves, carbon deposits in cylinders, bent or deformed connecting rods, incorrect timing belt installation. 6. Other reasons: Air conditioning system, automatic transmission, etc., which increase engine idle load, clogged catalytic converter, imbalance in rotating components such as the crankshaft and flywheel.