Loud squeak when accelerating

[Trich923]

I am getting a loud audible squeaking when pressing accelerator while at about 35 mph. Anyone else? It's very annoying and going to take it in to be looked at while having recall work done.seems like it occurs when the engine goes from v4 to v8.

[txab]

Might be the annoying exhaust flapper valve

[scott19677]

Yep. flapper valve.

[chuckl1218]

Exhaust "adaptive valve"...several threads on the topic

http://www.gm-trucks.com/forums/topic/153020-exhaust-adaptive-valve/

[ds109]

Trish923

I have the same problem. My 2016 silverado just turned 3,000 miles today and it's been chirping for about a week. I've been on other sites claiming the same problem and it is the "adaptive valve" directly behind the muffler. When it the engine switches between V4 & V8 modes is when this occurs and if you accelerate quickly you'll here it as well. I read a forum where someone put a clamp around the valve to hold it open and the chirping went away and their low-end acceleration improved. I may have to try that myself.

[sk]

Here is the TechLink info telling the techs how to put a bolt in the valve to hold it open:

 

http://sandyblogs.com/techlink/?p=3296

 

But others on here have said they had their exhaust replaced and the sound went away for a while but eventually came back.

[Badnico35]

Yea I get the same thing, but it’s whenever I press hard on the accelerator. Is there any way to remove the flap. It’s like a metal on metal on metal squeak.