Why does my car shake?
There are a number of different reasons your car will shake. The most common reason is due to tire balance. This is most often felt at higher speeds (50+mph). If the shaking is only felt when braking, the problem is most likely from the brakes. Finally, the shaking could be due to an engine misfire.
There is a lot of confusion around tire balance. The tires are the rubber part that is mounted to the metal wheel or rim. When tires are replaced, they are balanced on a special machine with wheel weights. The weights are installed on the wheel to counteract any irregularities in the tire and wheel. During normal driving, the tires take a lot of abuse, and sometimes the wheel does as well. This may cause the tire to become out of balance. Just like a washing machine with too much on one side wobbles and makes noise, a loss of tire balance will cause your car to shake.
When you apply your brakes, the brake caliper pushes the brake pads against the brake rotor and slows the car. For a variety of reasons, the brake rotor can become uneven, so when the brake pads contact the rotor, they bounce up and down. This vibration travels through the suspension and throughout the car. This shaking will only be felt when braking. Depending on the wear, you may feel it at high speeds or low speeds. You may notice the shaking only through the steering wheel, brake pedal, throughout the car, or any combination of these.
Most of you have heard the word misfire, but may not fully understand what it means. For a real understanding you need a basic understanding of how an engine works. The fuel and air are pulled into the combustion chamber. The piston compresses the air/fuel mixture and the spark plug ignites the mixture. This forces the piston down creating power. The used fuel is pushed out the exhaust and new fuel and air is pulled in. If any of these steps are unsuccessful, the engine will not run right and misfire. Engines are carefully designed to be properly balanced (when they are running properly). If they are not running properly, aka misfiring, then there will be a vibration. Many people experience this vibration mostly at a stop. A misfire will almost always cause the check engine light to turn on.
Is car shaking dangerous?
Any of these problems are cause for concern. The shaking from a tire balance or brake issue can cause extra wear on the suspension and drivetrain components, which will cause most costly repairs. A misfire can also cause other damage to the engine and to the exhaust system if not remedied shortly after this occurs.
Does your car shake while driving, braking, or idle?
Timing matters. Knowing when the shaking happens is key to diagnosing the issue. In general, the wheel balance will happen while driving, the brake issue will happen when braking, and the misfire will always happen, but is more noticeable at a stop.
How to fix car shaking
Now that you’ve identified the timing, here’s how to fix car shaking with each issue:
- A wheel balance issue can often be resolved with a wheel balance, but sometimes the tires or wheels will need to be replaced.
- The brake issue is resolved with new brakes. The problem usually lies in the brake rotors. Due to the cost of replacement, we usually recommend replacing brake pads at the same time.
- The misfire can be caused by a multitude of problems. On modern cars, the most likely cause are ignition coils. The misfire is diagnosed by first retrieving fault codes and performing the necessary tests. Once the problem is identified we can recommend the fix.
Can I prevent car shaking?
All of these problems are caused by circumstances beyond you, as the driver. You can’t control where the potholes are that may cause a tire balance issue. Poor-quality parts may lead to brake problems, but high-quality parts can cause the same problems, although much more infrequently. The misfires happen due to worn parts and are beyond your control. A normal inspection may show signs of these failures before you experience a problem, but many times they happen out of the blue. Give us a call if you are experiencing shaking in your car, and we’ll get you back to driving safely.