[AutoPenalti]

Hey y’all,

First time here and I would like to say how proud I am to be a Camaro owner.

Now for the lowdown, I recently bought an SS after upgrading from the 1LT. I’ve noticed an odd sound coming from either the engine bay or the exhaust. I was able to capture the sound immediately after shutting off the engine, but this sound tends to happen when I press on the throttle as well.

https://youtu.be/sblVMZwcPVk

https://youtu.be/24AFYPXP8vo

https://youtu.be/zbE8YqZfSxw

Again the noise from these videos occur upon pressing on the throttle. Whether I press on the throttle from stop (stop sign or stop light), or letting off the throttle and then a couple of seconds later hitting it again while cruising.

As of last Saturday, I’ve gone to the dealer and they were able to somewhat replicate the problem (of course it doesn’t want to make any noise when I’m at the dealership) one of the GM Engineers mentioned it could have been an exhaust valve. So he lifted the car and noticed the exhaust was loose and tightened it up, as well as gave me new headers (car is still under warranty so I wasn’t charged for it). After I took it back, the squeak came back again.

Noise occurs in any of weather and road conditions. My newbie guess seems to be occurring either in the exhaust valve or the serpentine belt.

After scouring for hours, I noticed this Beamer user had somewhat the same “short squeak” issue EXCEPT his seems occur when the engine turns on, the opposite of my problem.

https://youtu.be/s5BPB1G9ME4

Which begs the question: WHAT THE HECK COULD THIS POSSIBLY BE?

[Lithias]

As someone whose extremely familiar with the exhaust squeak issue, I have one question, and one thing for you to try.

When you put the car in accessory mode (hold the ignition with foot off the break), and go into the sound management settings (assuming you have the NPP option), and you switch between track and stealth, does it squeak?

If it doesn't, then it may be the AFM valves or could potentialy be the throttle body.

[AutoPenalti]

Originally Posted by Lithias

As someone whose extremely familiar with the exhaust squeak issue, I have one question, and one thing for you to try.

When you put the car in accessory mode (hold the ignition with foot off the break), and go into the sound management settings (assuming you have the NPP option), and you switch between track and stealth, does it squeak?

If it doesn't, then it may be the AFM valves or could potentially be the throttle body.

Well, I don't have the NPP since I have the 1SS, and while driving I usually have it on touring, the sound seems to occur whether it's in tour, sport, track, or snow/ice mode while driving or shutting off the car. (I'm assuming it's because of the butterfly valves that would make that noise if I had it to begin with?)


I'd also like to point out that the squeak doesn't seem to occur until after about ~10-20 minutes of driving, after the engine is warmed up.

[Lithias]

Originally Posted by AutoPenalti

Well, I don't have the NPP since I have the 1SS, and while driving I usually have it on touring, the sound seems to occur whether it's in tour, sport, track, or snow/ice mode while driving or shutting off the car. (I'm assuming it's because of the butterfly valves that would make that noise if I had it to begin with?)


I'd also like to point out that the squeak doesn't seem to occur until after about ~10-20 minutes of driving, after the engine is warmed up.

Well you may not have NPP, but is your car an automatic?

If it is, you still have AFM valves, so it could likely be one of the AFM valves.

[AutoPenalti]

Originally Posted by Lithias

Well you may not have NPP, but is your car an automatic?

If it is, you still have AFM valves, so it could likely be one of the AFM valves.

Yes it is an Automatic. What I find annoying is that this seems to occur frequently, even on my way to the dealership for them to check it out. When I tell them what the issue is, I tell them that the way to replicate the noise is to drive around for a bit and listen to the squeak. The GM engineer literally took the car for a test drive for about 15 minutes and told me he couldn’t hear the noise. As soon as he said that, he pressed on the gas and break at the same time and you could hear it immediately. It was very faint but it was enough for him verify what I was talking about. He tried it again and of course, the noise could not be replicated. I told him to shut off the engine to hear it and of course, the noise didn’t appear. I would have thought it would have even sounded louder considering where he and I were at it was a pretty “echo-y” place. His theory seemed to be it was an exhaust issue, he noticed that the exhaust was a bit loose and tighten it up. He also was nice enough to give me new headers. I will ask them to check the AFM valves. Again I've been only to capture the noise once the engine shuts off (only because I can hear it more pronounced in a quiet area rather than a busy street) This car is still under warranty until May 2020. I'm at 29940 miles. So I guess I got that going for me at least.

[AutoPenalti]

So I was able to finally replicate it while driving, as stated the noise can be produced when engaging the throttle as well.

https://youtu.be/lCwb_vpDcXI

Here’s another one with a quieter surrounding. Notice the pronounced squeak upon accelerating.

https://youtu.be/WUdLXSlss9w

[Lithias]

Originally Posted by AutoPenalti

So I was able to finally replicate it while driving, as stated the noise can be produced when engaging the throttle as well.

https://youtu.be/lCwb_vpDcXI

Here’s another one with a quieter surrounding. Notice the pronounced squeak upon accelerating.

https://youtu.be/WUdLXSlss9w

Definitely sounds like the AFM valves or it could be the throttle body.

You should try figuring out if your car makes the noise on the V4 to V8 switch when accelerating or if it makes it when going from V8 to V4 while cruising. There is a dash view that shows you what mode you are in while driving.

It really sounds to me like it's the AFM valves. So if it squeaks when you do what I said above, and it squeaks, it's the AFM valves

[AutoPenalti]

Originally Posted by Lithias

Definitely sounds like the AFM valves or it could be the throttle body.

You should try figuring out if your car makes the noise on the V4 to V8 switch when accelerating or if it makes it when going from V8 to V4 while cruising. There is a dash view that shows you what mode you are in while driving.

It really sounds to me like it's the AFM valves. So if it squeaks when you do what I said above, and it squeaks, it's the AFM valves

It seems to only happen when it switches from V4 to V8. But then how does it explain the same exact noise right as the engine shuts off?

Upon further researching with the AFM valves, this guy has the issue I’ve been hearing while driving. Except his seems to be on certain modes, I have the same issue as he does when he has it on “sport” mode.

Mine seems to occur on any mode, I want to try and see if changing it manual would disable the noise.

https://youtu.be/t0dysI0tHZU

I wonder if the engine noise shut off is all apart of that. It’s almost the same, if not, exact noise.

[Lithias]

Originally Posted by AutoPenalti

It seems to only happen when it switches from V4 to V8. But then how does it explain the same exact noise right as the engine shuts off?

Upon further researching with the AFM valves, this guy has the issue I’ve been hearing while driving.

https://youtu.be/t0dysI0tHZU

I wonder if the engine noise shut off is all apart of that. It’s almost the same, if not, exact noise.

Like I said, I have had my own issues with squeaking exhaust valves and the noise definitely matches a squeaking valve. Ask them if they have a way to get into the ECU and actuate the AFM valves with the engine off. If they squeak, they will try to lube it, but if it's not done right, it will come back. If it comes back, demand they replace the exhaust under warranty.

[Wilka_SS]

#PIC6289A

Some customers may comment on a Check Engine Light (CEL) or an exhaust noise.
Upon further inspection, dealership technicians may find a P12FD or a P12F0 set.
Cause
This concern may be caused by an exhaust actuator that was installed but the learn procedure was not completed. This concern will occur on new vehicles with low mileage, or on vehicles that recently had service work done to the exhaust system.








Then give them this bulletin number also:

#16-NA-003

Some customers may comment on hearing a squeak or chirp noise coming from the rear of the vehicle. The noise may be reported as being intermittent.
Cause
The noise may be caused by the opening/closing of the exhaust values during normal performance.
Additional Option RPOs
Chevrolet – Equipped with LT4 Engine, LGX Engine / NPP Exhaust, LT1 Engine / N10 Exhaust or LT1 Engine / NPP Exhaust
Cadillac – Equipped with LF4 or LT4 Engine


Confirm that the front or rear/tail pipe valves are the cause of the condition by activating the flow control function of the exhaust system.
Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in SI.
Use GDS to verify the exhaust flow control valves open and close when commanding the Exhaust Flow Control Valve On and Off, with a scan tool.
For Camaro and Corvette models, the engine sound management setting must be set to “Auto” to enable the scan tool to operate the valves.
Note: The noise may only occur during valve opening OR closing of a valve, not always both.
Command the flow control functioning numerous times and listen for any squeak/chirp noise, over and above the normal activation noise.
If the squeak/chirp noise is evident, continue ahead to the lubrication service procedure below.

[AutoPenalti]

Ugh, lubricant? I’ve searched all over that it barely lasts less than a couple days before the sound returns. I’d rather them just replace the whole exhaust together since I’m under warranty. I’ll keep you guys updated when I go in again on Saturday.

Thanks for this guys, ya’ll have been amazing!

Any others lurking are welcome to chime in for other users who have this problem, helps out a lot!

[AutoPenalti]

Narrowing down the noise, I've come across that putting the car on manual mode disables the sound. I check the service bulletin for #16-NA-003 but that seems to apply only for 2016's. Will the dealership still accept the bulletin for a 2017? Does it matter?

[GM-ACE]

Could be a belt tensioner or pulley. I found a squeaky tensioner one time that made that noise, with the same stepping on the throttle/shutting the engine down situation.

[AutoPenalti]

Originally Posted by GM-ACE

Could be a belt tensioner or pulley. I found a squeaky tensioner one time that made that noise, with the same stepping on the throttle/shutting the engine down situation.

That was my initial guess since I tend to hear a faint squeal (not squeak) during cold start, but for a pulley or tensioner to fail at 29k miles seems odd.