A well-serviced vehicle should accelerate smoothly and gradually. Even though the rate of acceleration varies with power, vibrations and jerks should never be part of the story.
If your vehicle shakes, jerks, or vibrates every time you get on the accelerator pedal to pick up speed, you have a significant problem that you should address as soon as possible.
What Could Cause Vibrations When Accelerating?
If you’ve narrowed down the vibrations to when accelerating, the culprits narrow down since you no longer have to worry about specific problems that will cause vibrations when braking.
The most common causes of accelerating vibrations include:
Damaged CV Joints
The first reason that could make your vehicle vibrate when accelerating is damaged CV joints. Constant velocity joints transfer power from the gearbox to the wheels. They are common in front-wheel drive vehicles and other all-wheel or four-wheel drive vehicles without solid axles and differentials.
Even though CV joints have rubber boots protecting them and the grease that keeps them working fine for thousands of miles, they are still prone to damage. Most damage happens when the protective boot tears and the grease leaks out, leaving the joint unlubricated.
Rust and uneven movement will lead to vibrations that could get worse as you accelerate since the CV joint will be under pressure to put more power to the ground.
Problems With the Motor Mounts
Many car vibration woes stem from the motor mounts – as long as they only come when the engine is under strain or when idling.
Motor mounts are heavy bolts joined by strong rubber bushings that attach the motor to the car’s frame. Since a running engine will constantly vibrate, the rubber bushings’ main job is to isolate these vibrations from transferring to the rest of the vehicle’s frame.
Dried up, torn, or partially damaged motor mounts aren’t as efficient. If they’ve just started failing, chances are you won’t feel vibrations when the engine is cruising at low RPM. However, any time it strains as you try to accelerate, the increased RPM and torque production will make the engine vibrate harder, and the almost failing bushings will have a hard time isolating them.
A Tire that is Out of Balance
Any slight imperfections in the diameter of a tire translate to massive vibrations since tires rotate so fast.
That is why tire balancing is crucial. Those extra balancing weights iron out the imperfections making your wheels rotate smoother than before.
Take your wheels in for balancing if you notice vibrations when accelerating or driving at specific speeds.
While some tire imperfections can be balanced, massive rim dents, tire bulges, or tire imperfections can only be fixed by replacing the entire wheel or tire. Your tire shop with the balancing equipment will advise you accordingly.
ProTip: If you take your wheels for balancing, it would be prudent to align them after installation. After all, a tire shop with balancing equipment most probably has alignment equipment. Quite efficient.
Bent Driveshaft or Axle
If your vehicle has rear-driven wheels, there must be a driveshaft under your vehicle transmitting power to the rear axle.
A slight bent or misalignment in this shaft will translate to massive vibration that gets worse as you accelerate.
The same happens if the solid rear axle has bends or kinks in it too. Bent axles will still vibrate on a front-wheel drive, though.
A Loose Lug Nut
The lug nuts can sometimes wreak havoc on your vehicle’s ride quality. Even though loose lug nuts will make wheels wobble and vibrate at any speed, the problem could be pronounced when accelerating.
Check your lug nuts frequently and ensure that they are torqued to spec. They tend to get loose over time, and you can sometimes torque them when changing tires fast.
Loose lug nuts are dangerous. They could easily wiggle others loose and eventually render the affected wheel inoperable.
A Misfiring Engine
The last common cause of vibrations as you accelerate is a misfiring engine. Luckily, the ECU monitors misfires and will throw a Check Engine light whenever it happens. If you check your dash and see a flashing Check Engine Light when the engine is vibrating, then your engine is misfiring.
The vibration gets less or disappears when you ease off the throttle. The car will also feel very sluggish when accelerating.
If you notice these symptoms and the flashing light, get your car towed or limp it to a very close garage. Driving a misfiring engine can be detrimental.
Can You Keep on Driving a Vehicle that Vibrates as You Accelerate?
While the car will keep moving for a while, you will eventually have to get the problem sorted as long as the misfiring engine does not cause the vibration.
The vibrations are not only a nuisance but will also put more strain on your vehicle leading to catastrophic failure. For instance, damaged CV joints or bent drive shafts will eventually shake themselves to failure.
Fast and comprehensive repairs will turn out cheaper as you will address the problem before it develops into something bigger.
How Much Does it Cost to Fix the Vibration?
The cost of repairing the vibration varies depending on what caused the vibrations in the first place. You will need a mechanic to inspect your car and narrow down the problem before figuring out how much it will cost to repair. Here are some estimates
- CV joints: $500-$1000
- Driveshaft: $500 to $1000
- Motor Mounts: $200 to $700
- Tires: $10 to $800
Can You Fix the Engine Vibrations On Your Own?
If you are handy and have handled other mechanical repairs before, you might be skilled enough to repair most car vibration problems. However, you will need help from professional shops to get things like wheel balancing done. DIY is also great if the car is not your daily driver and you don’t mind any downtime as you research some repair specifics.