What is an Onomatopoeia?
It’s a word that imitates the sound or action of the thing that it describes.
If you’re reading this guide because your vehicle is grinding, then we’re sorry you couldn’t learn it another way. What causes a car to make a grinding noise when accelerating?
There are five main reasons a car might grind when accelerating. These reasons include the following:
- Transmission Issues
- Differential Problems
- Bad Wheel Bearing
- Damaged CV Joint
- Worn Motor Mount
Each of them will manifest a little differently, and each has its own unique fix.
Thankfully, in this guide, I will cover everything you need to know about the issues above, including how to resolve them.
Let’s start with the main causes and potential fixes now!
Table of ContentsShow
Does Your Car Grind When Accelerating? 5 Possible Causes And How To Fix Them
Cause #1 – Transmission Issues
There are a lot of different sounds a transmission might make, most of which suggest it’s going out. However, if you hear a grinding noise, it’s likely already too late.
An automatic transmission grinding noise while accelerating suggests that the planetary gear system is worn. If you know how the system works, then you should easily be able to understand how even the slightest bit of damage could throw things out of sync.
If you don’t, then watch the video below for a visual explanation.
Simply put, it stems from the speed of the wheels not being on the same page as the engine. It may grind the entire time you’re accelerating, or it may only do so in a specific gear.
Regardless, this is definitely not an issue to ignore unless you enjoy high repair bills (we didn’t think so).
How To Fix
As one of the most complex components of a car, working on an automatic transmission yourself is not recommended. If your car makes a grinding noise while accelerating and it ends up being the transmission, you’ll need to take it to a professional.
More than likely, you’ll have to have it replaced. Check out our previous article for an in-depth look at transmission repairs and how much they cost.
Cause #2 – Differential Problems
A differential is the part of your drivetrain that allows the wheels to move at different speeds. If this was not possible, handling your car would be unpredictable and dangerous.
Basically, a differential takes power supplied by the engine, and it splits it between each of the wheels, allowing them to rotate at different speeds. When it’s not working correctly, you might notice a whining sound.
As it worsens, it may start grinding (especially when accelerating or turning).
When this happens, it means that the internal gears of the differential are worn and have gone out.
How To Fix
Sadly, if it’s already at the grinding stage, you’ll most likely have to replace the entire differential.
If it’s only making a whining noise, it may be low on diff fluid, which provides lubrication so that the gears do not scrape against each other.
For more information on differential repairs and costs, check out our previous article here.
Cause #3 – Bad Wheel Bearing
A wheel bearing is part of the wheel assembly, which is what connects the wheel to the axle. Simply put, it’s a set of steel balls that sit within a metal ring. They allow the wheels to spin without creating too much friction.
If one of your wheel bearings is worn or damaged, you may notice uneven tire wear or poor steering and handling. The other indicator? A grinding noise (especially while accelerating or turning).
Ignoring a bad wheel bearing can lead to it locking up, which puts you, your passengers, and those around you in danger. Additionally, if left alone, it can cause further damage to your transmission, CV joints, and wheel hubs.
How To Fix
If it is determined that you have a bad wheel bearing, your best bet is to replace it. Thankfully, it’s not a complicated job at all, meaning that you can do it yourself if you feel comfortable.
Be sure to watch this video for a step-by-step guide.
Otherwise, having a shop perform the replacement should run about $300 (this can vary depending on the make and model of your car).
Cause #4 – Damaged CV Joint
Constant-velocity joints (also known as CV joints) are what connect the transmission to the wheels. They are used primarily on front-wheel-drive vehicles.
If your car makes noise when accelerating at low speeds and taking a tight turn (usually a clicking, knocking, or grinding sound), it is likely failing. If you ignore a bad CV joint, you might not be able to shift out of Park, which, as you might have guessed, is pretty crucial.
You may also notice vibrations while driving or grease on the inside edge of the tires. You should reconsider driving a vehicle with a bad CV joint, as you might lose control entirely.
How To Fix
If the CV joint itself is worn, the only option is to replace it. While the part itself is not very pricey ($150-$500), labor costs are ($500-$800 extra).
For this reason, if you’re willing to put in the effort, you should be able to replace it by yourself.
Cause 5 – Worn Motor Mounts
The average sedan engine weighs about 300 lbs. – and the engine mounts hold it in place. They’re made of metal, so they’re susceptible to corrosion, which leaves them vulnerable to breaking down or separating.
When this happens, your car might make a grinding noise when accelerating from a stop as the engine shifts. This can cause the serpentine belt (if your vehicle is equipped with one) to rub on the underside of the swirl pot hose.
As you might have guessed, if your engine is not secured, it will quickly lead to extensive repairs as the weight of it rests on other components.
How To Fix
Thankfully, having an engine mount repaired is pretty affordable. A shop should be able to spot-weld the problem area for less than an hour of labor. However, if you need to replace it, be prepared to spend as much as $800 for a shop to do it.
Doing so yourself isn’t too hard, and you’ll only have to spend between $100-$300 for parts. Check out this video for a step-by-step guide.
Mind The Grind? Get Rid Of It
Did you notice the common theme throughout this article? If your car makes a grinding noise when accelerating, and you ignore it, then be ready for a costly repair bill.
If your car makes a rattling sound when accelerating instead of a grind, check out our guide here for a detailed look at what it might mean and how to fix it.