So my dealer also confirmed the issue to be the fuel line issue that was identified. My service manager actually duplicated the noise for me at the dealership and pinpointed the exact cause of the issue. They have ordered parts. Great Service from the service manager at Dow Lewis in a Yuba City , CA. !!!!!
That's good news, yea let us know if actually solves the issue after you pick it up. On mine, the GM folks had advised to replace the muffler which didn't solve the issue. Thanks!
So my 2019 sierra has this high pitch squeal as well. Most prominent at 20-30mph while accelerator lightly depressed. My dealer has replaced the muffler and did not resolve the issue. Hopefully a solution from GM will come soon. Thanks
Does anyone know if the lights on the side mirrors on the 2019 Sierra light up when the headlights are on, like they do on the 2500's? In some pics they appear to and in others not?? Thanks