High-Probability Causes:
* Tires: This is the *most common* cause of vibration. Check for:
* Uneven wear: Look for cupping, feathering, or bald spots on the tires. Uneven wear causes vibrations at higher speeds.
* Tire balance: Imbalanced tires are a major culprit. Have them professionally balanced.
* Bent rims: Inspect the rims for bends or damage. Even a small bend can cause significant vibration.
* Driveshaft: A worn or damaged driveshaft can cause vibrations and a rumbling noise, especially at higher speeds. This is more likely if the vibration is felt more strongly in the rear of the car.
* Wheel bearings: Worn wheel bearings create a humming or rumbling noise and vibration that increases with speed. Listen carefully for a growling sound while driving. Jack up each wheel individually and check for play (movement) in the wheel.
* Transmission/Differential: Problems in these components can produce vibrations and noises, but these are often accompanied by other symptoms like difficulty shifting, slipping, or unusual noises from the transmission area.
Less-Likely (but still possible) Causes:
* Engine mounts: Worn engine mounts can allow the engine to move excessively, leading to vibrations that transfer to the chassis. This is more likely to cause vibrations felt throughout the car, especially at idle or low speeds.
* Steering components: While less likely to cause a truck-like sound, worn tie rod ends, ball joints, or other steering components can contribute to vibrations.
Troubleshooting Steps:
1. Start with the tires: This is the easiest and cheapest thing to check. Have them inspected, balanced, and rotated. If the vibration persists after this, move to the next steps.
2. Check wheel bearings: Inspect them for play and listen for unusual noises.
3. Inspect the driveshaft: Look for any obvious damage, wear, or loose components. This requires some mechanical knowledge.
4. Listen carefully to the location of the vibration/noise: Is it coming from the front, rear, or center of the vehicle? This helps pinpoint the problem area.
5. Professional inspection: If you're uncomfortable checking these components yourself, take your Ford Focus to a mechanic for a thorough inspection and diagnosis. They have the tools and experience to identify the problem accurately.
Important Note: Ignoring a vibration can lead to more serious and expensive damage. Don't delay addressing this issue. The longer you wait, the more likely it is that the problem will worsen.
