5 Car Noises That Could Be Cause for Concern

June 18, 2020

Whether it's the smooth hum of Subaru engines or the roar of the powerful turbo engine in the Subaru WRX STI, there's bound to be sound when you drive a Subaru. By this point, you probably have a good idea of how your engine should sound, which is why other, unexpected noises can be troubling. There are a variety of common noises that could signal car trouble, and finding out what they might mean can help you know how to proceed. With that in mind, we've put together this useful guide to common car noises that point to trouble.

5. Squeaking or Squealing

Shrieking is never pleasant to hear, and it could signal trouble in your car. Figuring out when you hear these sounds may help you pinpoint their cause. Does the sound only show up when you brake? If so, it's likely due to your brake pads being nearly worn out. Most brake pads have a built-in wear indicator that will squeal when it's time to replace the pads. But if you hear the squealing at other times, there are a few possibilities. One of the most common is a serpentine belt that is either too loose or worn down. Since the serpentine belt powers the alternator and runs a number of car accessories like the water pump, a bad belt is cause for concern.

If the cause of the squealing is the brake pads, the solution is easy: have them replaced as soon as possible. But if it's the other type of squealing, the best course of action is to pull over as soon as you can and have your car towed to the dealership. If the drive belt breaks while the engine is running, the broken belt can cause real damage in the engine compartment.

4. Rumbling

If you're experiencing a rumbling sound that's louder than normal, there are a couple possibilities. If it seems to be coming from the front of your vehicle, you may have an exhaust leak. This could mean that the pipes are cracked, or the exhaust manifold gasket is having trouble. Exhaust leaks are notoriously hard to pinpoint without the right tools, so this typically requires expert diagnosis.

If the rumbling sound is coming from the rear of your vehicle, it's likely due to a bad muffler. Driving with a damaged muffler is against the law, and likely to irritate everyone around you. In this case, replacing the muffler is the best course of action.

3. Grinding

If you hear a grinding sound from the front of your vehicle, it's likely the sound of metal rubbing against metal without lubrication or other protection. Most often, this sound is reported when a driver is stepping on the brakes. In cases like these, this usually means that the driver has ignored the squealing of the brake pads that we mentioned earlier, and the brake pad lining has worn off completely. At this point, the metal backing of the brake pads is pressing against the rotors. This can cause extensive damage to the braking system, as well as putting your safety at risk. Have your brake pads replaced and your brakes inspected and repaired immediately. We don't even recommend trying to drive to the service center: call for a tow truck instead.

If you hear a grinding noise when you're not stepping on the brakes, our advice is the same: have your car towed to the dealership. The noise could be caused by bad wheel bearings, a worn CV joint, or something else entirely. While it could be something as harmless as a bad AC compressor, it's best not to take risks with this sound.

2. Knocking

A knocking or pinging when you're driving is not a particularly encouraging sign. This is usually due to detonation. Detonation happens when part of the fuel and air mixture spontaneously combusts after the spark has already fired, causing two sources of combustion. The collision of these two can cause a knocking noise. There are a number of potential causes for detonation. One of the most common is using fuel with an octane rating that's too low. However, it could also be due to a lean air/fuel ratio (that is, too much air and not enough fuel), poor timing, or even a bad knock sensor! In any case, you should have your Subaru looked at immediately, as detonation could cause engine damage.

There is another potential culprit that's unrelated to detonation: worn bearings that cause rod knock. This means that the pistons may be rattling against the crankshaft, and it also requires immediate attention.

1. Tapping or Clicking

A tapping or clicking sound may be due to low engine oil levels or low oil pressure. If your engine is making this sound, pull over as soon as it's safe to do so and check your oil levels. If the oil is low, adding more oil can be a quick fix, but it's only temporary. You will need to take your car to the dealership to find out the cause of the low oil. If the oil levels are normal, it's likely that there's a problem with the oil pressure, and you may have to have the oil pump or filter replaced. If this is the case, it's best to have your car towed.