Does anyone have an idea of what this rumble/knocking sound might be?

[touchdown83]

There's a faint rumble or knock that's been happening over the last 1k miles or so. It only happens around 1200-1500 RPMs and when I'm applying light pressure to the accelerator. I have the icarsoft code reader and there are no relevant codes (only for fan, airbag indicator light, High speed CAN bus)

I'm just trying to figure out how worries I need to be. Thanks for your help!

Video 1

Video 2

Video 3

 

[RoverTide]

What motor? V8 or SC V6? Video 2 has the best audio, but its still tough to tell. Does it only happen under load? May try to post some videos of the engine bay with someone else working the accelerator.

 

[jlach993]

Do some more investigative work. See how often and when it is occurring(cold start/hot and seldomly/frequently).See if it happens at the same speed either when coasting or accelerating. I have a V8 so totally different sound profile in the cabin, although i do hear what you are talking about. I just can’t decipher whether this is engine or driveline related. More investigative work and videos please.

 

[jlglr4]

Pretty sure its the transmission heat shield. Known issue - the steel bracket holding the heat shield cracks and it will vibrate right at like 1280 rpms under load. I replaced one, then welded a second. If you get under the car and bang on it with your hand or a mallet, you’ll probably hear the vibration. Easy to replace yourself if you have the part.

 

[jlglr4]

Just listened to the last video and i’m 99% sure that’s the heat shield.