Jump to content
  • Sign up for FREE! Become a GM-Trucks.com Member Today!

    In 20 seconds you can become part of the worlds largest and oldest community discussing General Motors, Chevrolet and GMC branded pickups, crossovers, and SUVs. From buying research to owner support, join 1.5 MILLION GM Truck Enthusiasts every month who use GM-Trucks.com as a daily part of their ownership experience. 

Exhaust Flapper Noise - Will it go away eventually?


Recommended Posts

FYI, I don't know if it's because I've been putting more miles on the truck or because the weather is warming up, but the grumbling and rattling seems to have lessened to the point it's almost undetectable. I may just leave things the way they are unless it comes back when it's cold. Just like the transmission, it shifted like crap until I got about 1300 miles on the truck. Then it got better and better. Almost overnight. Weird.........

Link to comment
Share on other sites

  • 1 year later...

Hello ! I know this post is almost 9 months old, still I'm giving a shot.

 

I've  been experiencing quite the same issue with the flapper valve on my 17' Sierra 1500 for about few months now. When idling (from cold start), it make a rattling sound (which basically is the spring that rattles between the plates). By rotating it open (or close), it stops right away (see video : https://drive.google.com/file/d/1hnIOqZiJW_2hH9cbu5P9FsG36N74UVz9/view?usp=drivesdk  )

 

As you can see, the design (plates on each side of the spring) has slightly changed over the years (now more of a rounded shape, not square anymore), but it hasn't keep it from doing that annoying sound lol...

 

thumbnail_Screenshot_20180128-214808.thumb.jpg.a7eb14791ff2687d5d3c7ef0890be6d2.jpg 

 

Dealership says they can't do anything about it (of course they don't want to replace the whole exhaust)... and I don't really want to do a full muffler delete or changing the whole exhaust system. So after reading this thread, I thought I would clamp the valve open (and call it a day). Only question I got : I know I need to do a 1/4 turn first to open it, but do I turn it clockwise or counter ? 

 

Thanks !

 

Link to comment
Share on other sites

18 hours ago, Elevation_2017 said:

Dealership says they can't do anything about it (of course they don't want to replace the whole exhaust)

Find another dealer.  You have a valid complaint under warranty.  There is an existing PIT telling them to replace the cold side of the exhaust.  If they don't want to do it they are just giving you the runaround.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share



×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.