(Updated on December 20, 2019)
Normally, a car should not shake when the engine is running. It should provide the driver and passengers with a smooth and comfortable experience. So, whenever you experience shakiness coming from your car, it is never a good sign.
It doesn’t matter if your car is idling, accelerating, driving, or braking. Any time you experience car shakes while you’re in the car, there must be something wrong with one of its components or parts.
Fortunately, shaking rarely means there is a problem with the engine. It just means there is a problem with a component that the engine relies on.
Top 7 Causes of a Car Shaking or Shuddering
It’s possible to experience shakiness at different times when you’re in a car. Sometimes it’ll happen during all instances of idling, accelerating, cruising, and braking, while other times it will just happen during one or more of these instances.
Below are seven of the most common reasons your car shakes when idling, accelerating, driving, or braking. Most of the time, the culprit is easy to fix and will just require replacing one part.
1) Bad Engine Mount (Idling, Accelerating, and Driving)
Engine mounts are what connect the vehicle’s engine to the frame of the car. The mounts are also designed to absorb vibrations and shocks that come from driving on the road. These same mounts also connect the transmission as well.
As you can see, motor mounts are very important for the vehicle. If any one of them were to become too worn out or damaged, then the entire body of the vehicle will vibrate any time the engine is running. If one engine mount is bad, it’s only a matter of time before the rest fail as well.
2) Uneven Tire Treads (Driving)
The only parts of the vehicle which touch the ground are the tires. Each tire has treads on them which grip the surface you’re driving on, so that the vehicle can have better traction and stability.
However, tire treads are some of the most vulnerable areas of a vehicle because they’re constantly spinning on the ground. This means the treads will get worn out quickly and actually become almost smooth.
Once this happens, you’re going to experience lots of shaking which will only get more intense as you accelerate faster in the vehicle. Therefore, you will need to replace your worn tires with new ones.
3) Warped Brake Rotor (Braking and Driving)
If you have a warped brake rotor in your braking system, then the brake pads as well as the calipers can’t function properly. When you step on the brake pedal to slow down the vehicle in this situation, the uneven brake rotors won’t be receiving the proper pressure on all parts of the disc.
Instead, you will experience lots of shakiness as the brake pad hits uneven parts of the rotor as you apply pressure to the brake pedal.
Related: Best Brake Pads and Rotors
4) Loose Wheel Bearings (Driving)
Wheel bearings lubricate the wheels of your vehicle to prevent them from generating a lot of heat. If the wheel bearings become too loose, you will experience both noise and shakiness coming from the wheels.
It will also make your vehicle less stable, so you don’t want to let this go for too long before replacing your bearings.
5) Bad Drive Shaft (Driving)
Rear-wheel drive vehicles have a drive (propeller) shaft which delivers power from the engine to the rear wheels. If you’re driving a rear-wheel drive vehicle and your propeller shaft is not perfectly straight, then the entire vehicle will shake. A bent drive shaft is not something that can be ignored.
6) Bent Axles (Driving)
If you have a bent axle in your vehicle, then it will cause shakiness and vibrations. The car shakes will intensify as you accelerate faster. Axles can get bent if you regularly drive over rough terrain or bumpy roads or were involved in an accident. Since axles turn so fast, even a slight imperfection can cause noticeable shaking.
7) Brake Caliper Stickiness (Braking and Driving)
A brake caliper is used to push the brake pad against the rotor every time you step on the brake pedal. If a brake caliper were to stick and not release correctly, then your vehicle will shake as you drive. This shakiness will get worse as you go faster or step on the brake pedal.