Troubleshooting Problem

[Victor Ng]

https://drive.google.com/file/d/17joMNEUowMfOK9vOs80nF-Tvcvt7WOXq/view?usp=drive_link

 

Dear all,

I’m a new member. Recently, my 2018 Chevy Silverado 1500 LTZ 5.3L V8 65,000 miles started having a weird sound. I recorded the sound. Please help me identify the problem. Recent transmission fluid changed. The sound only appears at low RPM and around 20-30 miles driving with really slight gas applied or from a stop and applying a really slight gas, then it is gone after 15 seconds. Please help!!! Any valuable input is much appreciated. I brought the truck to my friend shop but when he test drive it, the problem did not happen..

[rav3]

Check your vacuum pump