Loud rattle from engine bay 2021

Jaolered · January 22

Hey all, 2021 Silverado 2.7. 70,000 miles. Lately I've started getting a pretty loud rattle from the engine bay, especially when engine is cold. Seems to subside a little once the engine is at full temp. I've attached a Google link to short video.

https://photos.app.goo.gl/j4vRZwr6uFk8AmbX6

My first thought was it's a bolt that fell through the engine compartment and landed on the plastic tray (I put a CAI in at one point) but I've dropped the trays and retrieve the one I dropped. No idea.

Booger T · January 22

Don't know what part of the country that you live in but if you have recently driven in snow/ice conditions and the weather remains cold it could be ice buildup underneath vehicle. Have had this happen on my last two trucks. A 2020 1500 and just recently on my 2022 2500 HD.

KARNUT · January 22

I don’t know how big the engine covers are on new GM trucks but I’ve experience rattling with them when cold. It can sound like knocking.

newdude · January 22

Sounds like maybe something going on with the rocker arms?

Have a read here - Abnormal Engine Tapping Sound – TechLink (gm-techlink.com)

Silverado4x4 · January 22

Sounds like a loose heat shield as once the vehicle heats up it expands and tightens itself up some. I had this same type of sound on my fathers-in-laws truck found to be a loose heat shield on the convertor did some adjustments with my hands and noise was gone.