Rattle after deceleration

[Morty]

I am having an issue on deceleration. I hear almost like a valve chiming around. Almost like there is a valve in the exhaust losing the pressure and unable to stay open. Not sure if we have any in the exhausts.

This problem is really really starting to irritate me. I hear it daily from passenger side. It makes no sound on idle or if i rev up. But coming down from speed i hear it.

I have an 06 Envoy Denali. Anyone have any ideas?

 

[The_Roadie]

What changes a lot on deceleration is vacuum. Have you looked inside at your air filter box and at the hoses?

 

[Morty]

Yeah. Just cleaned my filter today. Currently running a Volant 15760 Cool Air Intake Kit. With prefilter.

 

[Morty]

This chiming or rattling comes from underneath the front passenger side. If the truck is put into neutral it stops, if the vehicle downshifts to 1st it stops. Just for a little more info.

 

[The_Roadie]

Not sure about V8s, but the I6 has an exhaust manifold heat shield that can come loose and rattle. ANd other shields over the cat and muffler. Have you looked and wiggled down there yet?

 

[sBoddie]

Sorry to hear this, Morty. Sounds like what mine started doing a few months ago before it died Labor Day. Oil levels fine, but I would get this knocking/valve rattle on decel, or right before a shift @ ~2300 RMP. Same truck as you, but 2005. How many miles on yours? Mine = 176k. See crosslink @ <http://gmtnation.com/f26/what-other-vehicles-have-compatible-5-3l-dod-6074/>

Started the full thread @ trailvoy after the motor quit completely. Was wondering why it got so quiet over there. Good to see you're posting, Roadie!

 

[Morty]

I have not yet checked the shields. Other then just some visual looking. I will have to take a peak.

It has around 77k miles. I do not having knocking. Its a chiming/rattle. Windows need to be open to hear it.