Hearing grinding noises coming from your car is never a good sign. More often than not, it’s a signal that something's wrong with a rotating part. While some drivers ignore these moans and groans for fear of a costly repair, experience tells us that turning a blind eye is not the answer!
If your car is starting to make strange grinding noises, it’s time to see your mechanic. Leaving these warning signs unchecked can lead to bigger issues down the line and even impact the safety of yourself and those around you. Below, we’ll cover the top car grinding noises that you might come across and what each of them means
Grinding Noise Coming from the Engine
Whether it’s a crushing, rumbling or grinding noise, any abnormal sound coming from your engine should be treated as an alarm bell. Grinding noises, in particular, could point to problems with several different parts of the engine from the alternator to the water pump or even the power steering.
Your best bet is to pop the hood and isolate each section to determine the source of the noise. If you’re unsure where things are located, you’ll need to familiarize yourself with the owner’s manual.
The first thing you want to check is the alternator. The alternator works together with the battery and is responsible for supplying power to your car while it’s in motion. However, an aging alternator can often lead to grinding noises as the bearings, or other internal components begin to wear. Alternators are expensive to replace (costing upwards $1,000 depending on the car model), so if you’re hearing any noises coming from the engine, you want to rule this one out first.
If you don’t want to waste any time, you can often check this yourself. Turn off the engine, remove the fan belt, and try turning the alternator gently by hand. If the bearings feel rough or make a noise, it may be a sign they need to be replaced. You can also use a rubber tube to listen for any noises when the car is running (place one end near the alternator and the other end to your ear).
If the alternator seems to be in good working order, it’s now time to check the water pump. The water pump circulates coolant through the engine block and radiator, helping to maintain a safe operating temperature and prevent your car from overheating. The water pump uses pulleys, although it’s generally the car’s internal bearings that wear out and cause the grinding sound of metal on metal. Noise relating to the water pump can be difficult to hear while driving, although it becomes much more noticeable when the car is idle (with the bonnet open).
Finally, if after checking all of the above and you’re still hearing a grinding noise it may be related to your power steering. Power steering reduces the force required to turn the wheel using hydraulic pressure, which is typically powered by a rotary vane pump. The pump forces high-pressure fluid through the system, making it easier for the driver to steer. Most of the time, the problem relates to the power steering fluid. For instance, there might be small air bubbles in the fluid (causing the pump to whine and vibrate) or the fluid might be old and not pumping efficiently (lost its physical properties). Alternatively, it could simply be a lack of fluid in the power steering system.
Grinding Noise When Brake is Applied
If you’re hearing grinding noises when the brake is applied–take your car to the local mechanic immediately! Faulty brakes can endanger the safety of other drivers and yourself and can potentially lead to major accidents. You should never ignore any unnatural brake noises or irregularities.
Worn out brake pads are your main cause for concern and are very easy to diagnose. You’ll receive a warning squeal as the pads wear away–right before the metal backing plate starts rubbing against the brake disc. This causes a very loud grinding noise (metal on metal) whenever you put your foot on the brake. If it gets to this stage, your car is now dangerous to drive. You’re also looking at costly repairs since the discs may need to be replaced too. Get onto it early and take your car to a mechanic for a thorough inspection.
Grinding Noise When Turning
Are you hearing a loud clicking or grinding noise when turning left or right at slow speeds? Then you might have a bad constant-velocity (CV) joint. CV joints play a critical role in transferring power from the transmission to the drive wheels. There are two CV joints on your car: an inner CV joint that connects the driveshaft to the transmission and an outer CV joint which links the driveshaft to the wheels. Typically, the outer CV joint will fail first as it bears more pressure and is more prone to damage from road debris. If you see grease leaking from a small crack or dark grease sprayed over the inside of your wheel rim, there’s a good chance the outer CV joint boot is failing.
The inner CV joint is rarely the culprit. But when it is to blame, you might experience the car shuddering from side-to-side or a clicking/grinding noise when driving and turning. The noise will usually get louder as you accelerate into a turn. It’s critical that you get this checked out, as a damaged inner CV joint can lead to an undrivable vehicle that easily loses control.
If you’re hearing grinding noises when turning, you should also check the condition of your wheel bearings. Wheel bearings are situated between the axle and the wheel, and minimize friction, allowing for smooth movement while driving. A grinding noise when turning may mean that the wheel bearing is worn out and should be replaced as soon as possible.
Don’t Ignore the Warning Signs
While some noises may not be too serious and easily fixed, others can point to more sinister problems that make your car unsafe to drive or unreliable. Either way, if your car is moaning and groaning–bring it in and get it looked at by a reliable mechanic right away.