Squeak when throttle is applied

[Steve Allen]

i have the same issue on 2014 gmc sierra and sounds like dealer is a lost cause any other ideas on how to fix.

i also have a 2004 chevy silverado with 389 thousand on it and it 

has no squeak lol

[Gartho33]

So it seems like I have the same chirp when I slow down and then accelerate shortly after. After reading some other comments, and then driving it again, I do believe it’s when it goes from V4 to V8. Does holding this flapper valve open fix that issue? If so, how do you do it?