Odd noise heard mostly at idle/stop lights etc..

[Baileysdad53]

Hey all! This is my first post! I’ve got a 2005 Chevy Tahoe LT 5.3 4X4. This truck runs and drives beautifully! Transmission was rebuilt about 10k miles ago. I’ve been noticing a rather annoying noise, almost rumbling, humming/vibration when sitting at idle. RPM’s stay strong around 550 ish with no fluctuation at all. Once I start driving again the sounds disappears until I’m stopped again! Transmission shifts flawlessly but this sound has me stumped! Pop the hood and it’s definitely not coming from the engine itself , sounds like middle to rear. I’ll post a video, I’ll apologize for the rain noises lol!
I’m just hoping someone will be able to help me crack this! https://share.icloud.com/photos/0200AMpBdXS75EMWcIIJGbgew

 

[Fless]

What is the loud noise I hear a couple of times during the video? Sounds like a door opening, or the shifter being moved.

 

[Baileysdad53]

That was shifting from park to neutral. Wanted to see if the noise changed

 

[OR VietVet]

Welcome to the forum from Oregon

Is the sound the same no matter what gear it is in when sitting and idling? And also the same when in neutral and park?

 

[Baileysdad53]

Yep! Stays the same. Sometimes it makes the noise for 30 secs then stops for a few and starts again. I notice it a lot at red lights/ drive thru’s and just sitting parked

 

[OR VietVet]

Have you had the transmission people listen and test drive? If you did not have the noise till transmission work, well, I would start there. Get a mechanic's stethoscope and listen all over. You are lucky that it makes the noise in any gear, sitting still.

 

[Baileysdad53]

I will have it taken to a shop for sure. I purchased the truck a few weeks back. My buddy’s dad owned it before. Maybe I’ll take it back to the shop the rebuild was done at. Do you think it’s trans related ?

 

[Baileysdad53]

It’s just crazy because other than the noise, the truck drives perfect! No issues shifting whatsoever. Even rolling down the interstate 85 + mph smooth as can be

 

[Fless]

If it has air suspension in the rear, it may just be the compressor running.

 

[Baileysdad53]

If it has air suspension in the rear, it may just be the compressor running.

That would make a lot of sense, now I feel like an idiot, but how would I be able to find out if my truck is equipped with that?