If your car is making a whirring noise from the engine or exhaust, it could indicate that a moving component is wearing out or there’s an issue with the exhaust system. Whirring sounds usually get louder with engine speed and can point to problems such as worn bearings, belts, pulleys, or airflow restrictions. While your car may still run, ignoring the noise could lead to serious mechanical damage or costly repairs.

What does it mean if you hear a whirring noise?

A whirring noise is often caused by rotating parts in the engine or exhaust vibrating or rubbing due to wear or imbalance. It can also result from loose components, failing accessories, or airflow turbulence in the exhaust system.

Common causes of a whirring noise from the engine or exhaust

• Worn alternator, power steering, or water pump bearings
• Loose, damaged, or slipping serpentine or timing belt
• Faulty idler or tensioner pulley
• Exhaust leak or partially blocked muffler
• Cooling fan motor or clutch issues
• Transmission or differential bearings (if noise changes with speed)

Why do you need to fix this problem quickly?

Whirring noises can indicate early signs of bearing or belt failure. If left untreated, this can cause sudden breakdowns, overheating, or even engine seizure. Early diagnosis helps prevent more extensive and expensive damage.

How do you know when to get it checked?

You should book an inspection if:

• The whirring noise changes with engine speed or acceleration
• The noise continues when the car is idling
• It gets louder over time or occurs with other symptoms
• There’s reduced performance, vibration, or warning lights on the dash

What happens during an assessment?

A mechanic will:

1. Listen to and locate the source of the noise
2. Inspect drive belts, pulleys, and bearings for wear
3. Check exhaust joints, gaskets, and mounts for leaks or vibration
4. Test accessory systems such as alternator, water pump, and power steering pump
5. Advise on any parts requiring repair or replacement

How much does it cost to fix?

Costs vary depending on the source of the noise. A simple belt replacement may cost $150–$300, while pulley or bearing repairs can cost $250–$600. Exhaust system repairs typically range from $200–$800+.

Is it unsafe to drive with a whirring noise?

It can be. If the noise comes from worn engine components or belts, a sudden failure could leave you stranded or cause further mechanical damage. Exhaust issues may also allow harmful fumes into the cabin. The problem should be diagnosed and repaired promptly.