I have a strange new sound coming from my car and I am wondering if anyone else has experienced this. It sounds like someone is bending and releasing a spring, or maybe a diaphragm is expelling air. It happens every few seconds, then might pause for a while and then it starts again. It seems to happen more when the car is cold. It happens when I am accelerating or coasting but sometimes it happens specifically when I hit the brakes and you can feel something of a clunk in the brake pedal. It usually stops after a few minutes of driving. I can't be sure but it sounds like it is coming from the driver side front (left hand drive).

I was guessing that it might have something to do with the master cylinder because of the diaphragm sound but this is a wild guess.

Is this a known issue?

 

I think this is going to need a sound clip posting.

As you can feel a 'clunk' through the brake pedal, I would get the suspect LHF corner wheel off and check for loose/sticking caliper. The 'spring' and 'diaphragm' sounds makes me think internal damper fault or worn damper mounting/spring isolator.

Graham

 

I originally said "master cylinder" in my post. I meant the "power brake booster".

Thank you Graham for your post. I will pull the wheel off and take a look. I'm not sure how easy it will be to get an audio clip. The noise isn't very loud.

 

Have you recently had any service done? Or did it just come out of knowwhere?

 

To gkubrak, I recently replaced the lower control arms.