What Causes Engine Shaking in Ford Focus?

[LaCole]

Ford Focus engine shaking may be caused by: 1. Carbon buildup in the throttle body; 2. Abnormal water temperature; 3. Spark plug issues; 4. Clogged fuel injectors; 5. Low cylinder pressure; 6. Open circuit in high-voltage wires; 7. Dirty air filter. An engine is a machine that converts other forms of energy into mechanical energy, invented in the UK. It can refer to either the power generation device or the entire machine including the power unit. The Ford Focus is a Class A family sedan. As a compact car under the Ford brand, it enhances Ford's global brand position with its excellent chassis and handling. The vehicle features a large sunroof, one-button start, TPMS tire pressure monitoring, parking radar, and a leather-wrapped steering wheel.

[DelBrianna]

My Ford Focus also had a shaking issue before, with the steering wheel vibrating at red lights. First, I checked the ignition system and found one spark plug had incorrect gap spacing. After replacing all four spark plugs, it improved significantly. However, slight shaking returned after a few days. A veteran mechanic diagnosed it as aging ignition coils, with one coil providing unstable power to a cylinder. After replacing the coils, the engine immediately ran smoothly. If shaking persists, he suggested checking throttle valve carbon buildup – I clean mine every 20,000 km with noticeable results. Also inspect engine mount rubber cushions for aging cracks; mine needed replacement after eight years when hardened rubber caused poor vibration damping, making the entire driver's seat tremble. As last resort, examine the fuel system – clogged injectors or overdue fuel filter replacement can also cause shaking.

[DeEmmett]

Don't rush to repair when encountering engine vibration in a Focus. Step-by-step troubleshooting is crucial. Ignition system issues are most common - spark plug erosion or ignition coil cracks can cause cylinder misfire, leading to unstable RPM. Next is carbon buildup, especially on throttle bodies and intake valves of direct injection engines, affecting air-fuel mixture ratio. I remember handling an old Focus last time with severe idle vibration - turned out to be a small crack in the vacuum tube causing lean mixture due to air leakage. Fuel system problems shouldn't be overlooked either - clogged injectors or low fuel pump pressure can directly cause cylinder deficiency. Engine mount deterioration occurs more frequently in high-mileage vehicles - observe engine movement amplitude during inspection. Sensor failures are less probable, but abnormal oxygen sensor data can also cause vibration.

[StRichard]

The Focus shaking is really annoying. Last month I just dealt with it, first was the spark plug issue, switching to NGK's improved it slightly. Later found the third cylinder's ignition coil was blackened, and upon testing it wasn't working at all—no wonder the engine was acting up. For self-inspection, focus on checking the coils for cracks and the spark plugs' condition. Also check the engine mounts; record the engine shaking with your phone and zoom in to see the displacement—if the rubber mounts are bad, vibrations go straight into the cabin. Don't delay carbon cleaning; I usually remove and clean the throttle body myself, saving hundreds. Fuel issues are easily overlooked—try adding a fuel additive; if shaking reduces, it might be clogged fuel lines. For vacuum leaks, spray around pipe connections and listen for changes—a hissing sound means there's a leak. Following these steps can solve 90% of the cases.