[CAX3]

I have noticed lately that the brakes give a god awful squeal when slowing to a stop. It almost sounds like a siren. I have heard brake squeak before, but this sounded different. I did suspect the brakes as it only happens when slowing to s stop and as soon as the car is stopped, the noise stops.

I replaced the back brake pads because they were worn down and needed it.

The awful sound was thill there.

The front brake pads are getting thin, but they still have some life on them.

Then suddenly I noticed that the horrible sound goes away when I turn that fuel saving feature off. So it appears that the auto engine off/on feature is causing this horrendous sound when braking to a stop.

Does this feature have a tie into the braking system? If so, it is back or front, or both?

Im kind of at a loss for troubleshooting this. A google search didn't yield any real results.

Any help would be appreciated.

[KC87ZB]

There is no interraction between auto stop/start and the car braking system. If your braking system is making noises that bad you should inspect it immediately and minimize driving, there could be something significant in need of repair/replacement.

[n55david]

Originally Posted by Dan13X3

There is no interraction between auto stop/start and the car braking system. If your braking system is making noises that bad you should inspect it immediately and minimize driving, there could be something significant in need of repair/replacement.

this is correct.

you have brake problems, go get them fixed

[tracer bullet]

If you have low speed brake squeal, look up "bed-in" procedures and give one a try. Basically clean off the brake surface. The really low speed / light brake pedal pressure squeals come from everyday driving if you don't occasionally get aggressive on the stopping.

If it's not directly related to your speed when you use them (i.e. idling along at 5mph in both cases with the feature turned on and off) then you might have a different noise altogether that you think is from the brakes. Belt related most likely.

[RockymountainRob]

Originally Posted by CAX3

I have noticed lately that the brakes give a god awful squeal when slowing to a stop. It almost sounds like a siren. I have heard brake squeak before, but this sounded different. I did suspect the brakes as it only happens when slowing to s stop and as soon as the car is stopped, the noise stops.

I replaced the back brake pads because they were worn down and needed it.

The awful sound was thill there.

The front brake pads are getting thin, but they still have some life on them.

Then suddenly I noticed that the horrible sound goes away when I turn that fuel saving feature off. So it appears that the auto engine off/on feature is causing this horrendous sound when braking to a stop.

Does this feature have a tie into the braking system? If so, it is back or front, or both?

Im kind of at a loss for troubleshooting this. A google search didn't yield any real results.

Any help would be appreciated.

Start/Stop doesn't have anything to do with the squeal! I was told it's a common issue with M cars, the larger brakes do squeal with the slightest moisture on pads…

[pungo]

Originally Posted by RockymountainRob

Start/Stop doesn't have anything to do with the squeal! I was told it's a common issue with M cars, the larger brakes do squeal with the slightest moisture on pads…

AFAIK, the F25 M vehicles have the same exact brakes as non-M, actually, besides the cosmetic differences, the M has the same performance as a non-M. It's not a true ///M, that's why there's no ///M badge on the rear.

[CAX3]

Thanks for the replies. I think I have found the problem.

Its the PCV valve on the valve cover. It makes this god awful squeal, but only when the auto start/stop feature is turned on and I am rolling to a stop. Thats why I mistakenly thought there might be some connection between the auto start/stop feature and the brakes. I realized it wasn't the brakes when I turned that feature off and the noise immediately stopped.

I was able to find a video of someone with the same issue on YouTube. Ill put the link below for anyone who find this thread and has the same issue.

Thank you all for the replies.

[RockymountainRob]

Originally Posted by pungo

AFAIK, the F25 M vehicles have the same exact brakes as not-M, actually, besides the cosmetic differences, the M has the same performance as a non-M. It's not a true ///M, that's why there's no ///M badge on the rear.

Originally Posted by pungo

AFAIK, the F25 M vehicles have the same exact brakes as not-M, actually, besides the cosmetic differences, the M has the same performance as a non-M. It's not a true ///M, that's why there's no ///M badge on the rear.

Nope

[pungo]

Originally Posted by RockymountainRob

Start/Stop doesn't have anything to do with the squeal! I was told it's a common issue with M cars, the larger brakes do squeal with the slightest moisture on pads…

Originally Posted by pungo

AFAIK, the F25 M vehicles have the same exact brakes as non-M, actually, besides the cosmetic differences, the M has the same performance as a non-M. It's not a true ///M, that's why there's no ///M badge on the rear.

Originally Posted by RockymountainRob

Nope

Yup, sad but true...