# Why does my car shake when I accelerate?

**Verdict:** Drive to a shop this week

- **Most common cause:** Worn inner CV joint or damaged axle
- **Urgency:** This week
- **Typical fix:** $40-$800
- **Causes to check:** 5

## Quick answer

A car that shakes only when you press the gas, and calms down when you coast, most often has a worn inner CV joint on a front axle, an engine misfire under load, or worn engine mounts. Tire and wheel problems and, on rear-drive cars, a worn driveshaft joint are other causes. Get it checked within a week.

## What is happening?

Pressing the gas sends twisting force, called torque, from the engine through the transmission, axles and tires. Every part in that chain has to stay centered and tight under the extra load. A worn CV joint, a loose driveshaft joint or a collapsed engine mount lets something wobble only while it is being pushed, so the shake appears with the gas pedal and fades when you coast. A misfire does something similar from the engine side, with power pulses that skip.

It matters because the parts involved carry all of the car's driving force. A worn CV joint usually gets louder and shakier over weeks, and in rare cases it can break apart and leave the car unable to move. A misfire under load overheats the catalytic converter. Worn mounts let the engine move enough to strain axles, hoses and the exhaust. Catching it early usually means one part, not several.

## What causes it? The 5 most likely reasons

1. **Worn inner CV joint or damaged axle** (most common), $250-$700. On front-wheel-drive and all-wheel-drive cars, the inner constant-velocity joint on each front axle slides and flexes as the suspension moves. Once it wears, it wobbles under the twisting force of acceleration, causing a shudder that fades when you lift off the gas. A torn boot that lets grease out and dirt in is the usual start. How to confirm: The shake is strongest when accelerating from about 20 to 50 mph and disappears when coasting. Look behind the front wheels for a torn rubber boot or grease sprayed inside the wheel well. Fix: Replace the CV axle.
2. **Engine misfire under load** (common), $150-$600. A worn spark plug, weak coil or cracked plug boot may fire fine at idle but fail when cylinder pressure rises under acceleration. Each missed power stroke jerks the drivetrain, which feels like shaking or bucking going up hills or merging. It is common on engines past their plug interval and can set a flashing check engine light. How to confirm: The check engine light comes on or flashes while accelerating, and a scan shows P0300 or a cylinder code. The shake often comes with a loss of power and is worst climbing hills. Fix: Replace spark plugs and any failed coil.
3. **Worn engine or transmission mounts** (common), $200-$800. When you accelerate, the engine twists in the opposite direction to the wheels, and the mounts hold it in place. Cracked or collapsed mounts let it rock, which can shake the cabin, knock the axles out of line and cause a thump when you step on or lift off the gas. Age, heat and oil leaks speed up their wear. How to confirm: You feel a clunk when you press or release the gas, and a helper sees the engine lift noticeably when you briefly shift into Drive and Reverse with the brake held firmly. Fix: Replace the worn mounts.
4. **Tire or wheel problem** (common), $40-$300. An out-of-balance wheel, a bent rim from a pothole, a tire with a separated belt or a loose lug nut can shake the car. It usually appears at a certain speed whether or not you are accelerating, but a damaged tire can feel worse under the load of acceleration. It often follows a pothole hit or new tires. How to confirm: The shake depends on road speed rather than pressing the gas, often starting around 50 to 65 mph. Look for bulges on the tire sidewall, uneven tread wear or a missing balance weight. Fix: Balance wheels or replace the damaged tire.
5. **Worn driveshaft U-joint or carrier bearing** (less common), $150-$700. Rear-wheel-drive trucks and SUVs, and many all-wheel-drive vehicles, use a driveshaft from the transmission to the rear axle. Worn universal joints or a cracked center carrier bearing let the shaft run off-center, so it vibrates under acceleration, often from a stop. A clunk when shifting into gear or a squeak that follows road speed are typical clues. How to confirm: The vehicle is rear-wheel or all-wheel drive, the vibration feels like it comes from under the floor, and you hear a clunk when shifting into Drive. Grabbing the shaft with the engine off may show play. Fix: Replace U-joints or the carrier bearing.

## How to narrow it down at home

1. Note whether the shake follows the gas pedal or road speed. If it fades the moment you coast at the same speed, suspect an axle, misfire or mount; if not, suspect tires.
2. Look behind each front wheel with a flashlight for a torn CV boot or grease thrown around the wheel well and suspension.
3. Read the codes with an OBD-II scanner. A misfire code points to the ignition; no codes point toward the axles, mounts or tires.

## Is it safe to drive?

> **Drive to a shop this week.** You can usually drive carefully to a shop within a few days if the shake is mild. Stop driving and get a tow if the check engine light flashes with power loss, if the car starts clunking hard or pulling, or if a tire shows a bulge, because a failing axle or tire can let go.

## When does it become urgent?

- The check engine light flashes while you accelerate: ease off and drive gently to a shop.
- You hear clicking when turning or loud clunks when you step on the gas.
- The shake gets stronger week to week or now happens at all speeds.
- A tire shows a bulge, or the car pulls or wanders: stop driving and use the spare.
- Grease is spraying from a torn boot, or the car stops moving even though the engine revs.

## What will the repair cost?

| Cause | Fix | Typical cost |
| --- | --- | --- |
| Worn inner CV joint or damaged axle | Replace the CV axle | $250-$700 |
| Engine misfire under load | Replace spark plugs and any failed coil | $150-$600 |
| Worn engine or transmission mounts | Replace the worn mounts | $200-$800 |
| Tire or wheel problem | Balance wheels or replace the damaged tire | $40-$300 |
| Worn driveshaft U-joint or carrier bearing | Replace U-joints or the carrier bearing | $150-$700 |

Detailed breakdowns: [cv axle replacement cost](/cost/cv-axle-replacement), [spark plug replacement cost](/cost/spark-plug-replacement), [ignition coil replacement cost](/cost/ignition-coil-replacement).

## What to tell your mechanic

Tell the shop at what speed the shake starts, whether it fades when you coast, whether it happens in every gear, whether you hear clicks or clunks, and whether the car had recent tire work or a pothole hit. They will road test it, read codes and misfire counts, inspect the CV axles and boots, check the mounts, and spin-balance the wheels.

## How to prevent it

- Ask for a quick look at the CV boots at every oil change so a tear is caught early.
- Replace spark plugs on the schedule in your owner's manual.
- Have wheels balanced when you mount new tires and after a hard pothole hit.
- Fix oil leaks promptly, since dripping oil softens rubber engine mounts.
- Avoid hard launches and wheelspin, which load axles, joints and mounts the most.

## Trouble codes that often go with it

- [P0300](/codes/p0300): Random/Multiple Cylinder Misfire Detected
- [P0301](/codes/p0301): Cylinder 1 Misfire Detected
- [P0302](/codes/p0302): Cylinder 2 Misfire Detected
- [P0303](/codes/p0303): Cylinder 3 Misfire Detected
- [P0304](/codes/p0304): Cylinder 4 Misfire Detected

## Frequently asked questions

### Why does my car shake when I accelerate but not when I coast?

Because the faulty part is only loaded while the engine is pushing. A worn inner CV joint, a loose driveshaft joint or a collapsed engine mount stays quiet while coasting and wobbles under torque. A misfire under load acts the same way. A shake that stays when coasting points to tires or wheels instead.

### Can a bad CV axle cause shaking when accelerating?

Yes, a worn inner CV joint is one of the most common causes on front-wheel-drive cars. The shudder usually appears between about 20 and 50 mph under acceleration and fades when you lift off. A worn outer joint is more likely to click on tight turns. Replacing the axle is the usual fix.

### How much does it cost to fix a car that shakes when accelerating?

A CV axle runs about 250 to 700 dollars, spark plugs and a coil about 150 to 600, engine mounts about 200 to 800, and wheel balancing about 40 to 100 dollars at an independent shop in 2026. Driveshaft joints on rear-drive vehicles cost about 150 to 700 dollars.

### Is it safe to drive if my car shakes when accelerating?

Usually yes for a short distance if the shake is mild and steady. Get it checked within a week, because worn axles and misfires tend to get worse. Stop driving if the check engine light flashes, you hear loud clunks, a tire shows a bulge, or the car starts pulling.

### Can bad motor mounts cause shaking when accelerating?

Yes. When you accelerate the engine twists against its mounts, and worn mounts let it rock and pass vibration into the cabin. You may also feel a clunk when pressing or releasing the gas. A shop can check by watching the engine move while briefly loading it in Drive and Reverse.

### Why does my car shake when accelerating at high speeds?

A shake that starts around 50 to 65 mph and stays when you coast is usually wheel balance, a bent rim or a damaged tire. If it only happens while pressing the gas, a worn CV joint or driveshaft joint is more likely. A misfire under load can also show up at highway speed.

### Can a transmission problem cause shaking when accelerating?

Sometimes. A torque converter that shudders when its clutch locks up can feel like driving over rumble strips at about 30 to 50 mph under light throttle. Old or wrong transmission fluid often causes it, and a fluid service may help. Axles, mounts and misfires are still more common causes.

### Why does my car shake when accelerating from a stop?

Shaking right from a stop often points to worn engine or transmission mounts, a worn inner CV joint, or on rear-drive vehicles a worn driveshaft U-joint or carrier bearing. A clunk as you pull away supports a mount or driveshaft problem. A misfire can also show up as a stumble from a stop.

### Can wheel alignment cause shaking when accelerating?

Not usually by itself. Bad alignment more often causes pulling and uneven tire wear. But the pothole hit that knocked the alignment out can also bend a wheel or damage a tire, and those do shake. Uneven tire wear from poor alignment can also add vibration over time.

### Can I replace a CV axle myself?

Yes, on many front-wheel-drive cars it is a moderate DIY job with jack stands, a large axle nut socket and a torque wrench. It takes a few hours and you may lose some transmission fluid. Seized parts, ABS sensor wires and torque specs are the usual pitfalls, so follow a repair manual.

## Sources

- [Car Care Council: Car care guide](https://www.carcare.org/car-care-guide/)
- [NHTSA: Tires](https://www.nhtsa.gov/equipment/tires)
- [AAA: Approved Auto Repair](https://www.aaa.com/autorepair/)

## Other car problems

- [Why is blue smoke coming from my exhaust?](https://diagxcar.com/symptoms/blue-smoke-from-exhaust)
- [Why does my car smell like something is burning?](https://diagxcar.com/symptoms/burning-smell-from-car)
- [Why does my car crank but not start?](https://diagxcar.com/symptoms/car-cranks-but-wont-start)
- [Why does my car hesitate when I accelerate?](https://diagxcar.com/symptoms/car-hesitates-when-accelerating)
- [Why does my car jerk when I accelerate?](https://diagxcar.com/symptoms/car-jerks-when-accelerating)
- [Why is my car leaking oil?](https://diagxcar.com/symptoms/car-leaking-oil)
- [Why does my car lose power when accelerating?](https://diagxcar.com/symptoms/car-loses-power-when-accelerating)
- [Why does my car shake at idle?](https://diagxcar.com/symptoms/car-shakes-at-idle)
- [Why does my car shake when I brake?](https://diagxcar.com/symptoms/car-shakes-when-braking)
- [Why does my car pull to one side?](https://diagxcar.com/symptoms/car-pulls-to-one-side)

## Repair costs

- [CV axle replacement cost](https://diagxcar.com/cost/cv-axle-replacement): $250-$700
- [Spark plug replacement cost](https://diagxcar.com/cost/spark-plug-replacement): $120-$450
- [Ignition coil replacement cost](https://diagxcar.com/cost/ignition-coil-replacement): $150-$400

## How long parts last

- [How long do tires last?](https://diagxcar.com/how-long/tires): 40,000-60,000 miles
- [How often should you change your spark plugs?](https://diagxcar.com/how-often/change-spark-plugs): 30,000-100,000 miles

## Trouble codes that lead here

- [P0307 Cylinder 7 Misfire Detected](https://diagxcar.com/codes/p0307)

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Source page: https://diagxcar.com/symptoms/car-shakes-when-accelerating
Updated: 2026-11-03
General information, not a substitute for a qualified mechanic.