Hi all,
I was driving down the highway when I hear something (bolt or some small part/piece) fall off the vehicle and bounce of the car on to the road. The car's been fine. However, ever since this incident, I feel like my exhaust is not as loud as before. Specifically, the exhaust is much more deeper and baritone and lacks the high pitched wail that existed perviously. I know a lot of the forum members mentioned the rattle when accelerating (which was also present in my vehicle), but that appears to be gone following this incident. Any insights as to what may have happened? I'd like to gather as much information as possible before I visit the dealer soon. I miss the sound of my exhaust... Thanks in advance!!

 

Why don't you just get under the car and have a look at the exhaust valves?
They are in plain sight outboard of the exhaust pipes (but before the muffler) and you can see them without even having to raise the car.
If a bolt or something else has "fallen off" it should be fairly obvious.

 

Thanks OzXFR! Will take a look and let you know.

 

Captain Obvious!

 

Probably muffler bearing got stuck

 

if you have the active exhaust your valves most likely failed. This has happened to me 5 times and the exhaust gets a lot deeper and more dirty sounding, go back to a few of my posts for a video comparison of before it failed and after. If you are under warranty take it to them and they should replace the catback. if not go for the VAP system as buying a factory system is overpriced.

 

Thank you all for your information. I checked for any visual signs of missing or broken parts, and didn't see any. By the way, my car does not have the active exhaust. Does that make the cause any different? I will take to the dealer later next week. Hoping this does not adversely impact any other parts of the car.

On a separate note, if not equipped with an active exhaust, does it mean that it's always on? Or is it the other way round?

 

There are three types of exhaust system on the V6:
1. Plain (not active) with no on/off valves. Similar in sound to the active exhaust in quiet mode with the valves closed but a little louder.
2. Active with valves, but not switchable. By default in quiet mode but opens the valves and goes to loud mode around 4,000 RPM or if you put it in Dynamic mode.
3. Switchable active, you can switch between quiet and loud mode any time you like regardless of revs or Dynamic mode.
It sounds like you have the "plain" version with no valves at all, and if so I have no idea what could possibly have "fallen off" to change the exhaust sound!

 

Thanks OzXFR. My car is definetely the "active with valves" type. Then I assume the cause is still the valve?

 

So I just visited the dealer and they were not able to find any visual defects near the exhaust. They even took me under the lift and showed how the valves were properly functioning by having someone press on the throttle above 3000-4000rpm. He even checked for any error codes that may be recorded but not sufficient to turn on any warning lights on the dash and found none. I also think that my hearing something fall off was coincidental - maybe I just happened to drive over some pebbles on the road. I'm afraid because there are no visual showing of any defect, I may not get it fixed. Any suggestions? Any help would be greatly appreciated!

 

Well, if you were shown that the valves were operating with a change in throttle position, where does the problem lie? Is it that despite the movement of the valves the sound of the exhaust did not change? If the sound did change as you were observing the valve operation, then logically there is no defect there, no?
What is the "it" that you fear will not be fixed?

 

No changes to the exhaust note above the 3000-4000 rpm range... so it looks like whatever is not working is something other than the valves.

 

This may be obvious, but: The exhaust note will only change at ~4000rpm if the loud button is switched to the off position. In loud mode, the valves are always open and there will be no stepwise change in sound at ~4000rpm.

 

Yeah, but the dealer demonstrated to fstik that the valves were moving (visually). Doesn't that indicate that the loud button was OFF during the test?

Or are you just reminding him that the aural change in sound when driving should only be heard when the exhaust button is off?
And, how does selecting DYNAMIC affect the 3K valve change? Does that mode open the valves earlier, making the "3K sound test" invalid?

 

Yes, just reminding him of that fact. Can’t answer regarding Dynamic mode on the AT. On the MT, dynamic mode does nothing more than turn the loud button on, stiffen suspension, steering and increase throttle response.

 

So just to make clear, my car does not have the active exhaust button. But is equipped with an exhaust that is "active with valves, but not switchable. By default in quiet mode but opens the valves and goes to loud mode around 4,000 RPM or if you put it in Dynamic mode" as described above by OzXFR.

Wonder if there's a fix to this or if I just have to suck it up and live with it.

 

Don’t think you mentioned what year your car is. For the first few years, an electric vacuum pump (and solenoid) controls the valves. Removing power to the pump (by removing fuse F43) leaves the valves open 100% of the time. (I have active exhaust, but not switchable active exhaust.)

I installed a wireless relay that allows me to switch F43 in or out with a fob. In the vert, leaving the valves open all the time produces a lot of drone at highway speeds, so leaving F43 out all the time isn’t great. I added the relay mainly because my valves became squeaky/grindy, and the vacuum pump is buzzy.

Happy Thanksgiving! Time to start making pies...

 

Belated happy thanksgiving... Mine's a 2017 Coupe V6S without the active exhaust button but with the non-switchable active valves.

 

After reading throughout this and if the dealer says its not your valves, my only other explanation is your catalytic convertors. Mine have gone bad three times and when they are close to going bad even before the check engine light turns on, it will change the sound of the exhaust, to a deeper more dirty sound, which looses the high pitched whale at high RPM's. You could have even heard pieces of cat coming out or blowing out. or an exhaust leak before the cats as well.

 

Maybe that's the culprit. Are damages to the catalytic converter visible from the outside? If not, I think I'll just have to wait for the light to turn on (hopefully during the warranty period) and have it replaced.