Your car makes a humming noise when accelerating
While driving, you hear a low-pitched hum. As you accelerate, the noise gets louder – maybe it sounds like an aeroplane taking off – but after a certain speed the volume is consistent. When you make a turn, the noise gets louder; but if you turn the other way, it disappears.
What it could mean: This is most likely a wheel bearing noise. It’s often mistaken as an engine noise and one way you can tell is to watch your RPM gauge. As you accelerate, the RPM and speed gauges rise. Coast at a set speed, let off the accelerator and watch the RPM gauge drop. If the noise is still there, it’s definitely not coming from the engine.
Your car makes a droning noise
This droning noise doesn’t change pitch or volume while turning, but it’s louder as you accelerate.
What it could mean: This noise may be coming from your tyres – particularly if they’re old or poor quality. It could also be a sign that you have “feathered” tyres – a term that once described tyres with treads that are wearing unevenly. In turn, feathered tyres could be a symptom of a worn suspension component, causing tyres to hop up and down as you drive rather than rolling smoothly down the road.
Your car makes high-pitched squealing noise
Do you hear a high-pitched squeal, or perhaps even what sounds like a bird chirping when you first start the engine?
What it could mean: Your car’s serpentine belt is likely worn or cracked. Some vehicles have multiple belts including a separate one for your air conditioning. If you hear this noise only when you turn on the air conditioning, you’ll know there’s an issue with that belt. It’s also possible that the belt doesn’t have enough tension (either the tension needs to be adjusted or the belt tensioner is worn). If there’s not enough tension, the belt is slipping. Ever hear tyres squeal on asphalt when someone does a burnout? It’s the same idea.