Why Is My Car Making a Buzzing Noise?

Why Is My Car Making a Buzzing Noise?

A buzz is usually something vibrating against something else at a certain speed or RPM, rather than a part that's actually failing. Where the buzz comes from and when it shows up points to the source.

What the pattern tells you

• Buzz from underneath the car, changes with engine speed: Very often a loose exhaust heat shield — a thin metal panel that shields nearby parts from exhaust heat and buzzes when its mounting clips loosen.
• Buzz from the dashboard or vents, especially at certain fan speeds: Points to the cabin blower motor or a loose piece of interior trim resonating with airflow.
• Buzz that only shows up at a specific speed, then goes away: Often a resonance issue — something loose vibrating in sync with the engine or road at that particular RPM or speed.
• Buzz tied to the air conditioning running: Can point to the AC compressor or a loose component in the AC system.

Why it's worth checking

A loose heat shield is usually inexpensive to fix, but ignoring it means living with the noise indefinitely and risking the shield rattling loose entirely. A buzzing blower motor tends to get louder and can eventually fail.

What we check at Stellar Autoworks

We inspect the exhaust system and heat shields for loose mounting points, check the blower motor and interior trim for the source of cabin buzzing, and confirm whether the AC system is contributing to the noise.

If your car has developed a buzz on your Plymouth-area drives, schedule an inspection with Stellar Autoworks and we'll track down exactly where it's coming from.