Exhaust rattle fix

[Faucetman]

I developed an exhaust rattle on my F80 ZCP and naturally, took the opportunity to upgrade to an Akra . Well, after replacing the actuators, the rattle persisted. Finally found the root of the issue today and is this spring!

We temporarily placed a few millimeters of washers to increase tension- it worked- and now looking for the parts to no avail.

Any ideas? Anybody else experience this?

[Kilabyte]

Which part is that?

[Faucetman]

Originally Posted by Kilabyte

Which part is that?

Goes in between the actuator and the flap to keep tension. The spring actually is inside the barrel - you can see the cap on the other end. I guess '16 ZCPs don't use the 'c' style clip/spring that I thought it did.

Found this from Remus…

[Kilabyte]

At what RPM was it audible? Open valves, closed or both?

[Faucetman]

Originally Posted by Kilabyte

At what RPM was it audible? Open valves, closed or both?

Both but louder when closed. Also during acceleration. Start up sounds like what everyone has described- pure rattle- but driving, warm, open valves, sound like a bug buzzing by your ear.

[Kilabyte]

Originally Posted by Faucetman

Both but louder when closed. Also during acceleration. Start up sounds like what everyone has described- pure rattle- but driving, warm, open valves, sound like a bug buzzing by your ear.

Thanks.

Filing this as another "if this happens in the future I know where to start"

[Shubacca]

I used to get that same rattle on start up. Put my Remus on yesterday and that was resolved instantly since they use a proprietary connection between the valve actuators and the valves. I never narrowed it down to that spring, but knew it was the stupid OEM valves. With the actuators off the OEM rear section, those valves have a colossal amount if play. No wonder they rattled.

[Faucetman]

Originally Posted by Shubacca

I used to get that same rattle on start up. Put my Remus on yesterday and that was resolved instantly since they use a proprietary connection between the valve actuators and the valves. I never narrowed it down to that spring, but knew it was the stupid OEM valves. With the actuators off the OEM rear section, those valves have a colossal amount if play. No wonder they rattled.

Totally agree on the play. With that, I would've thought the spring would be higher gauge to maximize life. I'm sure it played a contributing factor moving to to the C-clip/spring design.

I may have to source this spring somewhere else. You guys know a spring store? 😀

[Faucetman]

Originally Posted by Kilabyte

Thanks.

Filing this as another "if this happens in the future I know where to start"

Mostly why I posted. Lots of info on the later design but none on this. Glad you got something out of it.

[JAI///M3]

You can try McMaster-Carr for springs. If you have a caliper to take precise measurements, that would help too.

[Enzian]

I want to thank Faucetman TopJimmy

They both helped me fix the rattle on my MPE. This post helped me figure out the issue and Jimmy knowledge is incredible.

I had to replace the barrell and the spring from an old exhaust which I had.

The bushing has a little notch at the bottom that allowed for the barrell to release.

Fyi. Bmw recommend to replace the whole exhaust.

[TopJimmy]

Originally Posted by crustaceans

I want to thank Faucetman TopJimmy

They both helped me fix the rattle on my MPE. This post helped me figure out the issue and Jimmy knowledge is incredible.

I had to replace the barrell and the spring from an old exhaust which I had.

The bushing has a little notch at the bottom that allowed for the barrell to release.

Fyi. Bmw recommend to replace the whole exhaust.

DIY saves the man a couple grand!
Thank you for the kind words. Happy to help.

[Drifter2090]

Originally Posted by TopJimmy

DIY saves the man a couple grand!
Thank you for the kind words. Happy to help.

Were you guys able to find a replacement spring to stop the rattle?

[noemon]

Well done for figuring it out. That's great to know.

Have you found the parts required for total resolution?

I had lost my sleep with the rattle on my M5 Akrapovic and spent the next morning trying to figure it out, I then proudly made this first video ever.

[Enzian]

Originally Posted by Drifter2090

Were you guys able to find a replacement spring to stop the rattle?

I had my original comp exhaust, so I just used that spring and barrel from one sidel. However, you could use a washer to create tension. Maybe can buy amazon spring kit ( not sure on quality of if this is a viable solution)

[MFNATIK]

Originally Posted by Enzian

I had my original comp exhaust, so I just used that spring and barrel from one sidel. However, you could use a washer to create tension. Maybe can buy amazon spring kit ( not sure on quality of if this is a viable solution)

I have the annoying rattle too on my CS exhaust. Will buying the Amazon C clip spring replacement help in this case?

https://a.co/d/2fqxRa5

[Enzian]

Originally Posted by MFNATIK

I have the annoying rattle too on my CS exhaust. Will buying the Amazon C clip spring replacement help in this case?

https://a.co/d/2fqxRa5

My MPE and comp exhaust did not have that type of clip, but I have heard that some use that clip. This is a pic that resembled my exhaust.

My issue was inside the little metal barrel which had a small spring inside. The spring was bad and did not have enough tension which made the barrel rattle.

[jfritz27]

I've got a CS with stock rear section, and I've definitely got the valve rattle (significantly attenuates when the valves open after warmup, but a lesser buzz still audible while driving next to barriers, etc).

Would anyone be so kind as to summarize the main troubleshooting steps for this? Seems like the loss of tension from the spring is one cause, but maybe others as well? If I don't have a spare exhaust laying around, any pointers on whatever washers/replacement parts might be needed would be greatly appreciated... thanks

[MFNATIK]

Originally Posted by Enzian

My MPE and comp exhaust did not have that type of clip, but I have heard that some use that clip. This is a pic that resembled my exhaust.

My issue was inside the little metal barrel which had a small spring inside. The spring was bad and did not have enough tension which made the barrel rattle.

Ah ok, I just confirmed mine has the barrel style same as your pic. So is there a spring we can buy and replace to take up the slack and pretension the valve? I guess those clips I bought are useless for this application.

[Enzian]

Originally Posted by MFNATIK

Ah ok, I just confirmed mine has the barrel style same as your pic. So is there a spring we can buy and replace to take up the slack and pretension the valve? I guess those clips I bought are useless for this application.

I am sure you could buy a spring maybe try amazon. I was lucky that I had my old exhaust and just used an old spring. Another method that might work is adding a washer to create tension.