Exhaust Valve Malfunction?

[AW335OME]

Hello everyone,

I have a 2015 Competition F10,

Recently, when my windows were down I noticed a 'squeaking sound' from the rear every time the car is in drive and I start to accelerate from a stand still.

So to test the source of the sound, from a standstill, I put my left foot on the brake, and I would tap the gas peddle with my right... every time the car sensed any pressure on the gas I would hear a squeaking sound coinciding at the same time.

I then had someone look into the exhaust pipes while doing the test and they confirmed exactly what I thought: the left exhaust valve was trying to open every time I put any pressure on the gas peddle and the valve would close as soon as I relieved the peddle.

In my M2 mode, the valves stay open.

Is this normal behavior? Do I need to lubricate the valve in order to remove the "squeak" ?

As a fix, I used the zip-tie method in order to keep the valves completely open. I mean I do enjoy the louder tone when starting and driving, but just curious is this normal or a malfunction? Thanks in advance.

[Nikolov]

I don't think the F10 has a setting to keep the valves open at all times, unless you had some custom coding done. Otherwise the valves open based on throttle input, so it's normal for the valves to close when you let off the pedal.

I only hear mine squeak when I shut off the car - they close several seconds after. They got squeaky while I had the OEM mufflers off for a year or so. I tried lubricating them, but they start squeaking again soon. It doesn't really bother me, as I only hear it once, after I park the car.

[technician117]

Originally Posted by AW335OME

Hello everyone,

I have a 2015 Competition F10,

Recently, when my windows were down I noticed a 'squeaking sound' from the rear every time the car is in drive and I start to accelerate from a stand still.

So to test the source of the sound, from a standstill, I put my left foot on the brake, and I would tap the gas peddle with my right... every time the car sensed any pressure on the gas I would hear a squeaking sound coinciding at the same time.

I then had someone look into the exhaust pipes while doing the test and they confirmed exactly what I thought: the left exhaust valve was trying to open every time I put any pressure on the gas peddle and the valve would close as soon as I relieved the peddle.

In my M2 mode, the valves stay open.

Is this normal behavior? Do I need to lubricate the valve in order to remove the "squeak" ?

As a fix, I used the zip-tie method in order to keep the valves completely open. I mean I do enjoy the louder tone when starting and driving, but just curious is this normal or a malfunction? Thanks in advance.

The squeak is a common problem on these cars. It's just the shaft on the exhaust pipe valve. It's a dry fit. Spray some WD40 or similar on the shaft parts. It's usually good for a few months before the squeak comes back, depending on your environment. Driving in winter weather and salt will flush our your lubricant much faster than during summer months.

[Spartacus20k]

I also have a squeak that is haunting me currently, in my 2015 m5 csl. I have the Fi-exhaust, which has a mod that opens the rear valves full time, just FYI for Nikolov. Pretty sure this was a dealer installed upgrade to promote the competition package, as not all are equally endowed

I think my squeak is coming from the downpipe exhaust hang mount? If I daily drive calm like a bomb in "Comfort/Efficient" mode, no noises. If I roll past the X building, sorry Elon, in "SportPlus" mode making my M sound angry the noise begins and does not go away until I park. My co-worker who is a retired Sema car freak, thinks it's a bushing at the rear of the motor that the downpipes hang on and that it happens from my suspension going stiff, thus making the squeak start. I'm in research mode...