Q: Beeps, squeals, and whistle sounds in brakes

asked by on June 22, 2016

"It’s about a 1 mile round trip on my lunch break to home and back. While running in to grab my lunch, I left the SUV running. After getting into my vehicle, I pressed the brakes and heard a continual, long beep. It didn’t stop until I shifted back from drive and then into park again. I assumed it was just a glitch, so drove back to work. Three hours later, I’m driving home and stopped to fill up my tank. I got out of the car and as I did, I pressed the brake pedal (semi-way down) and there was that beep, but it had become a loud squeal instead and seemed to be coming from the brake system. --For the past ½ year, there has been a fluctuating whistle sound from the engine 24/7 (driving, idle, always in Reverse or Drive but a lower volume in Neutral). It sounded like an air leak, but nothing was escaping, it just sounded that way. The dealer told me that was normal. --In the mornings, the brakes always slightly squeaked when first driving. Plus they pulsated like going over tiny bumps when coming to a stop. Again, the dealer said that’s normal. --Back to the gas station… I pressed the pedal to try to replicate the sound and then I realized it was the brakes and they had a spongy feel to them, then they became hard -- just very different than they should be. I’ve never felt them like that before. Then the whistle started again. Then quit. The pads seem very hot. There’s no hard braking. What happened to change the brake sound and it’s consistency and what should I do?"

You should first have the brakes fully inspected and the brake booster and master cylinder diagnosed for any leaks or defects. If no problems are found, then check to see if the vehicle has the latest calibration for the powertrain control module. There has been problems with extended idle times with the A/C on and has caused problems that reprograming the computer has fixed. The whistle sound may be the brake booster check valve and should be checked to make sure it is not leaking or the engine has a leak in the hose to the valve from the engine. If you want to have this diagnosed, a technician from YourMechanic can come to your car’s location to diagnose the noise and make the correct repairs.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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

Pinpointing an oil leak - part coming off of the engine toward the back on the passenger side

Hello. From your description, it sounds like you are referring to the turbo intercooler. It is common over time for oil to build up in here due to wear in the turbo charger. I usually check the oil in the...

rough idle and low rpms at a stop light, but drives fine

Hello. This is very common on this particular vehicle. Typically it is caused by a dirty or failing throttle body. I have also had a few of these with a sticking thermostat which causes the engine to run cooler than...

Revving out of control

It sounds like you may have an issue with your idle air control valve on your 2011 BMW 328i. The idle air control valve is responsible for keeping the RPMs within a certain range during idling at a stop. If...

Related articles

How to Get Lincoln Dealership Certified
Lincoln dealerships offer automotive technician jobs to those who are Lincoln certified through UTI’s Ford Accelerated Credential Training program.
A Buyer’s Guide to the 2011 Lincoln Town Car
2011 2011 marked the final year for Lincoln’s aging Town Car. It offered an immense amount of space in the front and the rear, as well as the iconic style for which the line was known. Key Features Perhaps...
A Buyer’s Guide to the 2011 Cadillac DTS
The The 2011 Cadillac DTS is a full-size sedan that offers the comfort and luxury you expect from this automaker. It manages to combine a comfortable ride with tremendous amounts of cargo capacity in the trunk, although it isn’t without...