[vtirocz]

Is the TSB referenced in the first post still the latest or has it been revised since last year? Does it now reference 2017s as well? Has there actually been a design change to the ceramic pin area on most recent 2017 NPP exhausts to mitigate this problem?

I have not experienced the problem on my '17, but this thread has me concerned.

Original TSB: http://www.camaro6.com/forums/showpo...37&postcount=1

[vtirocz]

Here's the updated NPP service bulletin. Only minor updates to include 2017 model year and also added an optional Loctite for the procedure:

http://m.gm.oemdtc.com/TSB/SB-10082403-5448.pdf

[BradfordCamaro]

Mine started rattling again after the fix. (done last year)

Of course the dealer hears no abnormal noise and the epoxy is still in place....

Denied....

[TybeeSS]

This is so disappointing. My 1 month old 2017 is rattling. I started it today in stealth mode and it's a rattle can. Off to the dealer to get my car glued together. Glad I didn't spend north of 45 k on a car that rattles. Oops, I did.

[Eric SS]

Ugh, Mine just started doing this at less than 4,000 miles... I hate to bring it to the dealer for such an easy fix but I also hate to put epoxy on it myself and have them try to deny it in the future. The Epoxy is only $6.60 at Walmart so I might just bite the bullet and do it myself.

[TybeeSS]

Update. My car was built November 2016 as a 2017 model and any redesign was not applied until later. According to my dealer "only 5-10% of cars had this problem" to me that is an absolutely unacceptable failure rate. Maybe I am too picky but 10% seems high for something like this.
Hopefully gluing my new car will fix this problem.

[vtirocz]

Originally Posted by TybeeSS

Update. My car was built November 2016 as a 2017 model and any redesign was not applied until later. According to my dealer "only 5-10% of cars had this problem" to me that is an absolutely unacceptable failure rate. Maybe I am too picky but 10% seems high for something like this.
Hopefully gluing my new car will fix this problem.

Was there a design change made to later NPP exhaust valves? Mine is a 2017 1SS also built in 11/16, but I have not experienced the issue.

I would be happy to hear if there's an actual hardware design change to fix this, in case the issue ever comes up in the future.

[TybeeSS]

Originally Posted by vtirocz

Was there a design change made to later NPP exhaust valves? Mine is a 2017 1SS also built in 11/16, but I have not experienced the issue.

I would be happy to hear if there's an actual hardware design change to fix this, in case the issue ever comes up in the future.

Well i now have an "update to the update". Indeed 2017 models were "fixed" and my rattle is officially deemed " normal". The tech showed me two new vettes rattling in his service bay as well. I am so disappointed.

[TybeeSS]

I took matters into my own hands today since the rattle was so annoying I just couldn't enjoy my car fully. I also decided against putting more money into the car by fixing this issue with an aftermarket exhaust.
Followed the TSB step by step starting by using brake cleaner and wire brush, 5 minute epoxy and a qtip on a screwdriver to apply the glue. I also watched carefully to ensure no glue sealed around the flap and exhaust which could end up glueing the exhaust valve.
I only did the passenger side since that is the one that seemed to cause the most noise.

Interesting note here-the right and left side (at least on my 2017) appeared to be a bit different in the tolerances and design. The driver side almost looked like one seamless piece whereas the passenger side had a clear gap between the ceremic stem and flap.

I am happy to report that the rattle is 95% better! I only heard a slight rattle one time around 2k RPM so I went ahead and did the same process on the driver side and hope this cures it 100%.

[suzook]

As stated, if the procedure is done correctly, the rattle will be gone. I did mine over a year ago, 12k miles later, still rattle free. Do yourself a favor, and do it yourself. Making sure the surface is clean, is the most important step. I am sure the bozo techs dont give a $hit, and just apply the epoxy, with no prep.

[LT4Greg]

I have over 12,000 miles on my '16 and it does have the rattle too. But I'm not concerned with mine as I have the fuse pulled and the exhaust set to Track mode. I never thought that much about it because I figure it's the nature of the LT 1 under the hood to make some noise especially exhaust!!

[Mr. Meh]

Originally Posted by vtirocz

Was there a design change made to later NPP exhaust valves? Mine is a 2017 1SS also built in 11/16, but I have not experienced the issue.

I would be happy to hear if there's an actual hardware design change to fix this, in case the issue ever comes up in the future.

'17 ZL1 here, built in middle April of 17 .. Just noticed mine yesterday is rattling upon rev and start up. It's only the passenger side that's rattling.

[jasonct]

I get my car back tomorrow from my dealer who performed the NPP fix! I'm excited to see how I like the smooth rattleless sounds!

[enzia35]

Mine has started rattling. Sad.