What Causes the Focus Engine to Shake?
2 Answers
The reasons and solutions for the Focus engine shaking are as follows: 1. Ignition system failure: Spark plugs, high-voltage wires, and ignition coils may experience poor performance after a certain period of use. Solution: Check the condition of the spark plugs, high-voltage wires, and ignition coils, and replace the spark plugs if necessary. 2. Aging engine components: When the car engine is idling and the electrical system is turned on, it increases the engine load, causing idle speed to drop. To compensate for the shaking caused by the drop in idle speed, the engine will automatically increase the RPM slightly. Solution: Replace the engine mounts. 3. Unstable oil pressure: Abnormal fuel pump pressure or incorrect readings and poor performance of the intake pressure sensor can also cause engine shaking. Solution: Visit a 4S shop to check the fuel pressure and the intake pressure sensor for normal operation, and replace related components if necessary.
With over a decade of experience in auto repair, I've encountered many cases of Ford Focus engine shaking. The most common issue is spark plug problems—over time, filament wear or incorrect gaps can cause irregular ignition. Faulty ignition coils are also frequent culprits; unstable power delivery makes the engine shake like it's having spasms. A dirty mass airflow sensor interferes with readings, leading to incorrect air-fuel mixture ratios. Carbon buildup clogging fuel lines or intake valves disrupts smooth airflow. During inspections, start with the ignition system: remove spark plugs to check their condition and use cleaner for carbon deposits. In severe cases, relays or fuel pumps may need professional replacement. For prevention, change engine oil regularly, clean air filters, and monthly highway driving helps clear carbon buildup for city drivers. The engine is the heart of the car—don't ignore minor shakes as prolonged issues damage components and hike repair costs. Skimping on maintenance isn't worth it.
