Vibrations on a car should not be ignored. Whether or not the vibration represents a serious problem with the car, the vibration itself can cause damage to the vehicle. High-speed vibrations loosen bolts and connections, damage delicate components and wear your car out much more quickly than normal. You need to identify the cause of the vibration in case it is coming from a dangerous source and to prevent further damage to the car.
When a wheel is out of balance, the car vibrates within a specific speed range. Usually, the problem appears at higher speeds and intensifies as you accelerate. A wheel may be out of balance because a wheel weight has fallen off. However, road conditions also push wheels out of balance. Built-up mud or ice inside a wheel adjusts its weight distribution and causes this type of vibration.
A worn CV joint causes the car to vibrate when you hit certain speeds. The joint itself is covered by a protective rubber boot. Under the front end of the car, you should see a rubber boot covering the ends of the axle connected to each wheel. Look for any cracks or wear on those rubber covers. If you see any, or if you notice grease coming out from the boot anywhere, then you should have your CV joints inspected and serviced or replaced.
If you have a warped brake rotor, the car might start to shake and vibrate when you are slowing down. If you notice the vibrations primarily when braking, then this is the first issue to suspect. However, a rotor that is extremely warped might also cause vibrations when the brakes aren't on. If your usual vibration occurs at one speed but gets worse when braking, that is also cause to suspect a rotor.
A problem with the spark plugs in your car may cause the engine to vibrate, particularly at low rpm. This happens when spark plugs get dirty or when it is time to replace them. Also, a spark plug wire that is not connected properly could mirror this symptom. Make sure all the wires are attached firmly and replace the spark plugs to correct a shake you think is related to spark issues.
