Why Does the Car Body Shake on the Highway?

[StValeria]

Here are the reasons why the car body shakes on the highway: 1. Excessive carbon deposits. If there is severe carbon buildup inside the engine cylinders, it can lead to clogged spark plugs and valves, directly causing the car to shake at idle. If the car's acceleration performance has significantly declined and the shaking persists, consider cleaning the engine cylinders. 2. Fuel system failure. Unstable fuel pressure can cause fluctuations in the air-fuel mixture concentration, not only resulting in shaking but also unstable idling. First, consider replacing the fuel filter and then check the fuel pressure. If abnormal, the issue might be with the fuel pump. 3. Worn engine mounts. If the engine shaking becomes increasingly severe but the power output remains unaffected, the problem could lie with the engine mounts. 4. Misfiring is the most common cause of engine shaking. The issue may stem from faulty ignition coils or spark plugs. If the ignition coil malfunctions or the spark plug fails to fire for any reason, the car will experience shaking.