[bobfacs]

Here is service comments on the Dealer Service Invoice:
C/S that when vehicle swaps from 4cyl to 8cyl there is a chirp noise heard. Sometimes can hear on accell from a stop check and advise. Easier to hear the top down. Verified customer concern. Found exhaust actuator valves making chirp noise when opening back up once V8 mode engages. Remove and replace exhaust actuator valves and dry lube valve shaft and baffle in exhaust. Test drove vehicle. No noise heard at this time.

Part QTY 2 FP-NUMBER 84560761 DESCRIPTION ACTUATOR 3.640

The chirping noise decreased, but over time return.

Does anyone have any suggestion(s) to advise the dealership to attempt to fix the issue?

[FarmerFran]

Put the exhaust in Track mode (in the radio - just the exhaust) and see if goes away.

[He11bent]

I haven’t had this problem nor did I realize the exhaust valves would move with AFM. How many miles on the car when it began?

[bobfacs]

Around 2K, heard the noise while in the mountains.

[ember1205]

Depending on the options of the car, there could be 0, 2, or 4 actuators.

The two actuators that are tied to AFM mode are only present on automatic transmission cars. The two actuators on the exhaust are only on cars with NPP exhaust. What is the configuration of your car, and WHICH actuators were causing the issue?

Putting the car in Track Mode does nothing for exhaust actuators if your car does not have NPP, and has zero effect on the AFM valves being used (it will impact -when- they open on close, but it won't disable them).

[LT4Greg]

There maybe nothing the dealer can do about the noise since they already replaced the parts.

[ARCamaroGuy]

Mine does this (2020). At least I think it is what you describe. I thought it was just the sound of the valves closing and never questioned it. Mine does it a lot going from 3-4 or 4-5 puttering around town which is kind of annoying. I put the car in manual mode if I don't want to hear it. I really don't know if it can even be fixed. As much as I don't like it, it really is a minor annoyance for me. It's really the only thing I can think of that I don't like about the car.

[bobfacs]

I ran the exhaust in Track mode for the last week. For the most part, the sound is no longer happening. Sometimes as I come to a stop and the engine returns to an idle rpm, I hear a sound, maybe a light back fire.

I placed it back in the touring mode and the sound returned.

[LT4Greg]

It’s the sweet sound of that 6.2 liter LT1 making noise!��

[ember1205]

Originally Posted by bobfacs

I ran the exhaust in Track mode for the last week. For the most part, the sound is no longer happening. Sometimes as I come to a stop and the engine returns to an idle rpm, I hear a sound, maybe a light back fire.

I placed it back in the touring mode and the sound returned.

Track Mode adjusts a variety of different aspects of things from the motor back. It will impact whether the exhaust "gurgles" when decelerating or not and will also affect how/when the AFM will kick in and out (assuming it's an Automatic). It will also dictate whether the bypass butterfly valves on an NPP exhaust are open or closed and when the changes will occur. In order to know which actuators may be involved in the noise, more needs to be known about the configuration of the car as I mentioned in a previous post.