If you notice your car making a grinding sound when it accelerates, your issue is likely to do with your transmission, a problem with your differential, a bad wheel bearing, a damaged CV joint, or a worn engine/motor mount.

If your car makes a grinding noise when accelerating, possible causes could include issues with the transmission, differential, bad wheel bearings, worn CV joints, or loose engine/motor mounts.
Some of the
car repairs
needed for grinding noises on acceleration can be DIY, but others, like transmission issues, should be handled by a professional.

Common causes of a grinding noise during acceleration

Possible causes of a grinding noise during acceleration include:

Transmission issues

Differential issues

Worn or failing wheel bearings

Damaged or worn CV joints

Damaged or loose engine/motor mounts

Let’s take a closer look at each issue to help you diagnose the cause of your car’s problem.

Transmission issues

Your car’s transmission is responsible for controlling the amount of power transferred from the engine to each wheel.

The problem: The grinding noise when you accelerate likely has to do with your car’s planetary gear system. This system ensures that the speed of your car’s wheels match the speed of the engine.

If your wheels and your engine are working at different speeds (hence the grinding), this can cause significant damage to your transmission. You may notice this grinding during acceleration or just when your car is in a specific gear.

The solution: Unfortunately, if you’re noticing grinding that’s caused by transmission problems, you’re past the point of fixing it—it will likely need replacing.

Do not attempt transmission repairs or replacements yourself. Transmissions are complex, intricate machines and should be handled by professionals only.

The cost: Replacing your transmission with a new one will set you back $4,000 to $8,000, depending on the vehicle.

If you’re able to replace your worn-out transmission with a rebuilt one, this will likely cost between $2,500 to $4,000—but again, this will depend on the type of car you drive.

Differential issues

The differential is the part of your car’s drivetrain that allows your wheels to rotate at various speeds by taking power from the engine and delivering it to each wheel.

The problem: Grinding or whirring sounds can mean the internal gears of your car’s differential system are worn out. You’ll likely notice it when speeding up or turning your vehicle.

The solution: If you notice the grinding and the differential is found to be the culprit, you’ll have to replace it.

However, if you notice more of a whirring sound rather than grinding, the differential could just be

low on fluid

. Differential fluid lubricates gears so they don’t scrape together (which you’d notice when turning).

The cost: Depending on your car, replacing a differential will cost $1,500 to $4,000. If a fluid leak is the problem, this costs only $70 to $150 to remedy.

A bad wheel bearing

A wheel bearing is part of a wheel’s assembly and connects the wheel to its axle. Wheel bearings allow your car’s wheels to spin with a minimum amount of friction.

The problem: A grinding noise when accelerating and especially when turning can mean a

wheel bearing is damaged

or worn out. This can impact and hamper steering, handling, and cause uneven tire wear on your vehicle.

The best way to diagnose if this is the cause of your grinding sound is to drive at a low speed with the steering wheel turned fully to the right, then fully to the left. If the grinding or knocking sound is louder with the steering wheel turned in one direction and not the other, a worn wheel bearing is likely your culprit.

A worn-out wheel bearing can cause issues for your transmission, CV joints, and wheel hubs. It can also cause wheel bearings to lock up, which can put you and your passengers in grave danger.

The solution: You’ll need to replace the worn-out wheel bearing. If you’re handy with cars, you can do this yourself.

The cost: If you can DIY,

replacing a worn-out wheel bearing

will cost roughly $60 to $150, depending on the type of car you drive. If you get a mechanic to replace a wheel bearing, it will cost around $300.

The CV joint

Constant velocity (CV) joints

connect the transmission to the car’s wheels—mostly on front-wheel-drive vehicles.

The problem: If you hear grinding, clicking, or knocking as you accelerate, one of your car’s CV joints may be failing.

If ignored, your car can get stuck in park. Another tell-tale sign of CV joint failure is grease on the inner edge of your tires.

If you feel vibrations when driving, this could also be the CV joint. It can cause you to lose control of the vehicle.

The solution: If a CV joint is worn out, it must be replaced. Luckily, you can save some money and do this yourself.

The cost: If you take your car to a mechanic to get a CV joint replaced, the part itself will cost around $150 to $500 and labor will cost roughly $500 to $800. If you’re able, doing it yourself will cost much less, roughly $95 to $210.

The motor mount

The motor or engine mount is what holds an engine in place. A motor mount is a sturdy piece of equipment, as the average engine weighs a hefty 300 lbs. Motor mounts are made of metal, so they can corrode, break down, or become separated from the engine.

The problem: If you hear a grinding sound when speeding up, your engine mount could be the problem. This usually means that the motor mount has shifted or come unmoored and the engine is shifting around inside the engine bay.

A loose or unmoored motor mount can also impact your car’s serpentine belt, which can cause further damage by rubbing against the underside of the car’s swirl pot hose.

An engine that is loosened or separated from its mount can end up resting on and damaging other components—and that can be expensive to fix.

The solution: You can fix a worn or loose motor mount yourself if you have the know-how and tools—that is, you can spot weld it back into place.

The cost: Taking your vehicle to a mechanic to re-secure your motor mount will cost roughly $800 with labor costs. If you’re doing it yourself, you might pay roughly $100 to $300 for parts.

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Other causes of grinding noises during acceleration

As noted above, we’ve gone over the most common causes of grinding noise during acceleration. If none of the issues listed above seem to be causing the noise in your car, the issue could be:

Failing

Worn out

Bad

Damaged brake

damage

Low