Car Trouble: Diagnosing Shaking

Hands on the steering wheel of a classic car
Dulcie Wagstaff / Getty Images

If your car is shaking, it can be very frustrating. The causes can vary, but discovering why the shaking is happening is half the battle. Use this guide, organized by type of shaking, to help figure out what is causing the shaking.

Shaking at Speed

A common shake is a vibration that can be felt mainly through the steering wheel. This type of shaking usually comes on as your vehicle increases in speed. The steering wheel may start to vibrate, but the intensity can vary. This type of shaking can be dangerous as it affects your steering and may cause loss of control of your vehicle, especially if you have to make a sudden turn or stop to avoid a collision. In the long term, there are side effects to this shaking that will cause premature wear on many of your car's systems, from tires to transmissions. The following things should be checked, they are listed in order of severity (and repair cost!). 

  • Wheel Balance: Have a tire shop check and rebalance your wheels. An off-balance wheel can cause lots of vibration. This is a cheap fix if it's your problem. 
  • Shock Absorbers and Struts: Worn struts or shocks can cause an uneven driving condition and can result in shaking, porpoising, or a bouncy ride. 
  • Upper Strut Bearings: These are at the top of your front (and sometimes rear) shock towers and are accessed from under the hood. Most full-service tire shops can also check and replace these parts. Another vibration culprit. 
  • Ball Joints: Ball joints keep both your suspension tight while still allowing things to go up and down and turn from side to side. When they wear, shaking is definite. 
  • Tie Rod Ends: Tie rods connect your steering rack to the wheels (basically). The tie rod ends must pivot up, down and side to side. They keep both wheels tracking in exactly the same direction at all times. If your wheels are trying to go in different directions, you can get serious vibrations.

Shaking at Idle

If your car shakes before you put it in gear or while you're sitting at a light, something related to the engine is broken. Check for the following:

  • Motor Mounts: A broken or tired motor mount will cause your engine to move around too much. At low RPM, it can really get bouncy under the hood. This can be a minor or major repair depending on the vehicle. 
  • Fuel System: If the engine RPM seems erratic or drops suddenly, this can cause a shake or vibration. Troubleshoot your fuel system to see if this is a problem. 

Shaking While Accelerating

Vibration on acceleration can be a little scary. If the car shakes when you press on the gas, check these things first:

  • Transmission Fluid: Believe it or not, a low transmission fluid level can cause all sorts of bucking and jerking on acceleration. 
  • Transmission Filter: Same as above, but different solution.
  • Universal Joint: The U-joint at your driveshaft can become worn and develop excessive play. This is especially apparent on acceleration and needs to be repaired before you find yourself stranded.