Rattle, not sure if it's inside or out.

[BourbonNcigars]

Past the point of insanity here. Has me car shopping.

Have tried for 3 months to no avail. Due to the vast amount of road and wind noise this thing has, I can't pinpoint it. Even when someone else is driving and I'm in the back trying to find it. I can do something about the road noise, but not until this rattling sound is fixed or else it will simply appear louder.

1. Interior has been completely disassembled, including headliner, liftgate trim, and seats (doesn't mean I'm missing something, though). No change in noise.

2. Can't tell if it's from inside a body cavity or under the Tahoe.

3. Won't start until around 35mph and will continue at any speed after (I get a feeling this is the big clue).

4. Under 35 it simply will not rattle, no matter how rough the road is.

5. Seems to get louder on deceleration. Could be lower engine noise allowing it to be heard more easily.

6. Sounds like two pieces of tin foil rapidly contacting each other. Very faint, but easily heard.

Thoughts? I originally thought maybe the exhaust but the sound is so clear. Like it's not having to go through the floor to be heard. And I'd think if it were the exhaust it'd rattle with any movement, not just over 35mph.

 

[Doubeleive]

did you try banging on the cats? if one has a loose heatshield or if it is broken inside the noise it makes when bang on it will sound different

 

[ZACHBORIS]

what about the heat shield on an exhaust manifold? Mine seems to "ting ting , ping ping" every so often.... just a thought

 

[BourbonNcigars]

Have beaten on the cats and muffler. They can make a slight rattling sound when doing so, but wouldn't that happen at any speed if I can just hit it with my hand and make it rattle? And I had someone hit them while I was in the vehicle and didn't hear anything inside. Heat shields have been tightened and bent so they're not making noise.

I know noises can be misleading, but if I was forced to guess based on what I hear, it almost sounds like it's coming from the roof or high up somewhere on the passenger side rear. But when you get back there you can't localize it, which makes me think it's coming from the outside (no roof rack on mine, by the way).

 

[iamdub]

Set it up on jack stands and spin the wheels in gear until you hear the noise? If you hear the sound louder outside and under, crawl underneath while it's going on for a closer listen.

 

[Rocket Man]

Turn on some music dammit.