[Mobicoop]

I know this may come off as weird, but upon several occasions I hear a knocking, it seems to be emanating from the truck. Please help to
solve the mystery.
Mobi

 

[grullon10]

That is the vapor canister doing it job . It is part of the emisión system

 

[Stepside]

Could be the "Trunk Monkey" :duck::hide:

https://www.youtube.com/watch?v=JV-XEiUOjYE