NPP Valve Squeak
 

So over the weekend my NPP exhaust valves started squeaking when switching from tour to sport/track and when accelerating in certain gears at certain RPMs. It is a very loud squeaking noise and can be intermittent.

I found an old TSB for this on 2016s that has a procedure to lubricate the valves, so I made an appointment with my dealer to have it looked at and the procedure done.

Has this happened to anyone else with a 2018 or 2019 NPP car?

Does anyone have an updated version of the TSB? I dont know how to search for them but the one I have is #16-NA-003.

i had the "repair procedure" done, it was the epoxy fix. it made mine worse. so much so they ended up replacing the exhaust system. that was 6 months ago, its starting to make the noise again now.... love it

This is NOT the rattle. This is completely different from the rattle.

The squeak seems to be fixing itself, becoming less apparent. Not sure why it started happening, but did manage to show my dealer, so they will be lubricating the valves under warranty.

Just wanted to update incase anyone else ever has this problem.

Went to the dealer, they performed the service listed in the TSB even though it had nothing to do with my model year, and it fixed everything right up. No more squeaking valves when changing modes, accelerating, or decelerating.

Another update, the squeak has returned.....going to have the dealer lubricate the valves again. If it returns a third time, I'll push to have the exhaust replaced.

My car started doing this in the past month. Exactly as you described.



it's definitely annoying


I sprayed some lube around where I thought it was coming from and it stopped for approx 2 days


I'm WAY out of warranty so I might just live with it. It goes away for me in track mode

So the squeak returned after only two days. I have started the process with my dealer to have the exhaust replaced. Will update after replacement and a few hundred miles.

Quick update to this. GM approved to have the exhaust replaced, dealer ordered the exhaust, and now we wait. My next update will be after install.

Good to hear. At least they are replacing it under warranty.

Well after a weekend, the exhaust replacement seems to have fixed all issues. One thing to note, before the squeak started I could always hear the valves open and close. On the new exhaust I can't even tell, just the engine sound getting quieter. It's dead silent switching open to close and close to open.

I just started having the same issue on my 2108 2ss Camaro. I was just wondering if yours hasn’t made the sound since the exhaust was replaced? Also was all of the work covered under warranty? Just curious because I would like to get this fixed under warranty. Thanks.

I have the same issue. Dealer told me that GM didn't have a bulletin on it and they would wait until GM says what to do?

Well unfortunately I return to update.

I am now having a similar problem with the new exhaust except the opposite, it squeaks when the valves close, it's not as bad as last time, but it also still sometimes squeaks on opening. I am going to clean out the exhaust where the actuators are tomorrow with some IronX during my wash and see if it helps, because there is significant build up.

All my repairs were warrantied at no cost to me on the original exhaust.

If it still persists after a thorough cleaning I'll update again.

EDIT: Quick note that I only noticed this new squeak while parked and messing with the switch, could be a heat thing too, as the car was hot after my drive home. Didn't hear it at all when driving where as the previous exhaust the first squeak was while driving with the windows up with radio on.

I had the rattle and had the epoxy fix, then I cut out the AFM valves and still had it, then I finally seemed to mostly stop it with the epoxy fix. Then I did the new fix for the rattle where you grind off the ear, I havent heard the rattle since, but I still feel like there may be some kind of rattle at WOT but the engine is so loud its hard to hear it over that.

Anyway I have also always had the squeak also, its bad right before startup when the engine is still off, it also does it when your idling around in sport mode like when you said the valves start to close.