What causes the intermittent shaking of the Focus engine?

[SanDawson]

The reasons for the intermittent shaking of the Focus engine are: 1. Severe engine carbon deposits: Symptoms include poor engine performance, increased fuel consumption, and even difficulty starting; 2. Issues with the ignition system: Certain components or wiring of the ignition coil in the arc system may have open circuits or short circuits; 3. Unstable oil pressure: This can be due to insufficient engine oil, dirty oil, thinning oil, oil pipe leakage, oil pump damage, or excessive wear of its components. The Focus is a compact car launched by Changan Ford, with dimensions of 4647mm in length, 1810mm in width, and 1468mm in height, and a wheelbase of 2705mm. It is equipped with a 1.5L naturally aspirated engine or a 1.5T turbocharged engine, paired with an 8-speed automatic, 6-speed automatic, 6-speed manual, or 8-speed automatic manual transmission.

[LeAurora]

I've driven quite a few cars, and it's quite common for the Focus's engine to shake intermittently. Don't panic and rush for a major repair just yet. The most common causes are aging spark plugs or excessive carbon buildup, leading to uneven ignition, which is most noticeable right after startup. Another possibility is a faulty ignition coil—if it fails intermittently, the car can shake like it's dancing while driving. Additionally, loose or worn engine mounts can cause noticeable shaking when going over speed bumps or turning. The Focus's engine is particularly prone to carbon buildup, so regular throttle body cleaning can prevent many issues. To save money, you can check the spark plugs yourself; if you're experienced, replacing them isn't too difficult. If you're unsure, take it to a professional shop to read the fault codes with a diagnostic tool. Don't delay—prolonged shaking can affect other components, such as increasing fuel consumption and wear, or even triggering errors in the catalytic converter.

[LolaLee]

As a daily driver of a Focus, I find the occasional shaking quite annoying. It's likely due to worn-out spark plugs or faulty ignition coils, which are most noticeable during cold starts. Also, check the air filter; if it's too dirty and affects air intake, the engine will run unevenly and shake. Another common issue with the Focus is fuel system problems, like a clogged fuel pump or carbon buildup in the injectors, which can cause severe shaking after refueling. Loose engine mounts are also a frequent culprit, making the car wobble while driving. Last time I neglected maintenance, the shaking got so bad that the car broke down halfway—I really regret not addressing it sooner. I suggest trying to replace the spark plugs yourself; it doesn’t cost much. If that doesn’t help, get a diagnosis at the dealership. Also, using higher-quality fuel and occasionally driving at highway speeds to clear carbon buildup can save a lot of trouble.

[Blakely]

The car shakes intermittently, mostly due to ignition system issues, such as severe carbon buildup on the spark plugs or end of life, or intermittent faults in the ignition coils. Loose engine mounts can also cause this, especially on uneven roads. The Focus design is prone to carbon buildup, and poor air intake exacerbates the shaking. Fuel system blockages, like dirty fuel injectors or a failing filter, also lead to unstable operation. Start with a simple check of the spark plugs and replace them if needed to see if it helps. Inspect the mounts for cracks and repair them promptly to avoid bigger problems.