Skip the auto shop - Our mechanics make house calls

Q: Vehicle makes whistling noise when warm

asked by on

When the vehicle is warm, it makes a loud, high-pitched whistling noise from under the hood. It sounds like a vacuum leak.

A: A vacuum leak is a possibility but another ...

A vacuum leak is a possibility but another possibility would be an exhaust leak. Both can cause a whistling noise when the engine heats up. A vacuum leak is more likely to change with engine speed. A qualified technician, like one from YourMechanic, will be able to perform an inspection and a vacuum test to determine where the noise is coming from.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Battery light is on and car has no power steering

If the Battery Light is illuminated and the battery passes a load test, then you most likely have a faulty alternator; a charging system test would need to be performed to verify this. On the 2001 540i, the power steering...

Q: Strange sound in the engine

There should be a vacuum coming from the oil fill hole with the engine running. This is because vacuum is created inside the engine as the piston moves downward in the cylinder. Also, you should feel vacuum when holding your...

Q: Serpentine belt coming off

Hello. The oil that is spitting out from the front main seal is leaking onto the serpentine belt, and belt pulleys. This is causing the serpentine belt to slip off. The front main seal will need to be replaced with...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.