If your car shaking while accelerating, it is not unusual—especially in older vehicles or vehicles that do not get regular maintenance. This could indicate larger problems. Ignoring it could lead to damage to the parts of your car and safety problems when driving it.
So, the moment that you notice any vibrations when accelerating, you should take the car to your trusted mechanic. Fixing the issues early will likely save you a good amount of money, rather than waiting for the problem to get worse.
You should also familiarize yourself with some possible causes to get a general idea of how to diagnose the problem. This may also allow you to make the repairs yourself if it is a minor problem. You would definitely save some money.
So, what makes a car shake when accelerating?
Why does my Car Shake When Accelerating?
Note: Sometimes when cars are shaking when driving this can often mean something completely different than shaking when at a stop or when braking, so be sure to pay attention to when the shakes occur.
If your car is shaking when you accelerate, this is not only frustrating, it can also be a dangerous situation. Below are some possible causes of shaking.
#1. Damaged Inner CV Joint.
Your vehicle’s inner CV joint, which is at the end of the axle, is something you should examine if you are experiencing shaking issues. A damaged CV joint will cause your vehicle to vibrate under hard acceleration.
As the problem worsens the shaking will increase from slight to violent shaking especially if you are loading the vehicle. The issue can only be fixed by replacing your defective CV joint.
Without proper lubrication, the metal-on-metal contact eventually fails. The only resolution to the CV joint failure is to replace the CV joint or the entire CV axle.
#2. Broken Motor Mounts.
The main purpose of motor mounts is to attach a car’s engine to the vehicle’s frame. The secondary purpose of motor mounts is to dampen, or reduce engine vibration so you don’t feel the constant shaking or vibrating of the engine while running.
Motor mounts consists of a hard rubber material which allows them to absorb the engine vibrations while the engine operates. If a motor mount is damaged or broken it will not only allow excess vibrations in the car, but other components in the engine may also become misaligned or break from operating out of it’s proper positions.
You would feel a bad motor mount vibrating when idling, but the shaking can be exacerbated upon acceleration since the engine has to work harder. Replacing a bad motor mount should eliminate the vibrations.
Keep in mind that once a motor mount is broken or damaged, the remaining mounts will have more of a burden during operation, making them susceptible to damage or even complete failure.
#3. Unbalanced tires.
If you had tires recently installed and your car shakes while you’re driving it may be due to unbalanced tires. Each time a tire is mounted onto a wheel, it will never be the same weight all the way around.
To balance it, an installer mounts the tire/wheel assembly on a balancing machine and stick small wheel weights to the rim at designated spots to make the balance perfect. As the tire rotates, any slight weight imbalance turns into a small vibration.
At higher speeds, with the tire rotating at a much greater speed, vibration is easily noticeable, and your steering wheel will shake.
If your car vibrates while at a constant speed, and it gets worse at higher speeds, it is likely an unbalanced tire(s). It is also possible that one of the adhesive wheel weights just fell off. To correct this, simply take your car back to the tire installer and have them rebalance the tires.
#4. Loose lug nuts.
Loose nuts on one of your wheels could be another reason your car wobbles or shakes every time you speed up. Ignoring this situation can be much worse and potentially dangerous, losing a wheel while you’re driving.
Make sure you use a torque wrench and ensure each nut on each wheel is tightened to the recommended factory lug nut specs. If you don’t have access to a torque wrench, a regular lug nut wrench or tire iron will work too.
#5. Bent Driveshaft.
If your vehicle has rear-wheel drive (RWD), power is transferred from the engine to the rear axle and wheels through the driveshaft (propeller shaft).
As a result, if the driveshaft is bent or damaged (even slightly, which often happens due to an accident), it will cause shaking when accelerating from a stop and worsen as vehicle speed increases.
In most cases, driveshafts can’t be straightened, so replacing the driveshaft is usually the only option.
#6. Bent Axle.
If you run into a curb, large rock, or have some sort of minor accident, just because you don’t see any apparent damage doesn’t mean everything is ok. The incident could have bent an axle, and that is a very serious problem.
You will start to notice vibrations coming from the car that will get worse the faster you accelerate. Like the driveshaft, you will need to replace a bent axle right away before causing additional damage.
#7. Stuck Brake Caliper.
If a brake caliper on a wheel is bad and causing it to stick, it can most certainly cause brake shutter amongst other car vibrations. In this particular scenario, the steering wheel is the thing that will vibrate as you accelerate from about 40-50 miles per hour.
These vibrations will continue to get worse as you accelerate to faster speeds. After you stop, you will likely smell a burning odor from the vehicle.
If you suspect a stuck brake caliper, and I would suggest you can tell which wheel it is on by smell. You will need to inspect the entire brake system there paying close attention to the caliper bolts, slides and piston.
Sometimes the stuck components just need cleaning and re-lubrication, but if the brake components are at fault, they must be replaced.
#8. Torn or Disconnected Vacuum Hose.
This common issue can create very significant shaking or shuttering of a car while driving. When a vacuum hose gets disconnected or has an air leak from a small tear, the absence of the air pressure can create confusion for a number of sensors which can lead to misfires, backfires, lose power, and all sorts of issue when the engine does not run smoothly.
Check all hoses to make sure they are connected, aren’t torn or cracked, and if possible, attach a small hose clamp to re-affix hoses that are too loose on the fitting.
Vacuum hoses on turbocharged vehicles are also very susceptible to accidental disconnection. It’s very common to replace these vacuum hoses with stronger silicone hoses for good.
#9. Dirty or Worn Spark Plugs.
Dirty or fouled spark plugs can cause an engine to misfire. Typically the problem will first noticed when at a stop, however it may also cause a car to seem like it is vibrating while driving.
If you can’t remember the last time you changed your spark plugs, then it’s probably time too. If you remove one and see a bunch of dark build up on the tip, then there is a good chance the rest of your spark plugs are bad as well.
#10. Suspension Problems.
The suspension of a car is responsible for keeping the tires in contact with the road, providing a smooth ride, and absorbing all the bumps and shocks. If you have a problem with the suspension; you may very likely experience shaking or vibrations if you give it gas.
Some common suspension problems that would make your car shake and vibrate are:
- Worn Ball Joints. These are the pivots between the suspension and wheels; worn-out ball joints will often cause the car to shake.
- Worn Wheel Bearings. These are the bearings that allow your wheels to spin freely; with bad wheel bearings, your car will shake, especially at higher speeds.
- Damaged Shocks or Struts. These are the shock absorbers that help to keep your car stable; expect your vehicle to shake if the shocks or struts are damaged or worn out.
#11. Death Wobble.
Death wobble is an extreme shaking of a vehicle’s front end that can be caused by worn-out steering or suspension components, improper tire inflation, or other vehicle issues. Affects various types of vehicles, with the majority of incidents experienced by trucks, SUVs, and Jeeps.
If you are experiencing death wobble while driving, you should slow down by taking your foot off the gas or pressing the brake, and pulling off to the right side of the road, as it may cause an accident. Once it’s safe, have a mechanic diagnose the death wobble issue and address the issue to make the vehicle safe to drive again.
How to Diagnose Car Shaking
If your vehicle starts vibrating or shaking when you accelerate, you will want to address it before it becomes a bigger problem. Follow these tips to better assess the situation:
Visual Inspection
The first step will be to visually inspect the vehicle. Look for any physical damage or wear on the tires, steering components, and suspension parts. Look if there are any loose or broken parts in the area. Look for leaks or any other signs of trouble below the hood.
Test Drive
Next, following a visual inspection, you will want to take it for a test drive. Pay attention to the type of shaking you were experiencing, its location, and how bad it is.
Is it frontal or rear shaking? How low or high do you need to be driving to feel the shaking? Does it originate in the body, steering column, or maybe somewhere else?
Does the shaking increase in intensity as you accelerate? Does it only shake and vibrate on certain roads?
These questions can help you and/or the mechanic find the source of the problem.
Computer Diagnostics
If you are still unable to solve the shaking issue with a visual or test drive inspection, you might need to think about computerized diagnostics. A mechanic can use a computerized diagnostic tool to read any stored codes in the computer or to determine potential problems.
Remember, if you are unsure about what is causing the shaking or do not want to try diagnosing it yourself, it may be best to take the vehicle to a trusted mechanic for them to inspect it professionally.