Strange Noise Under My 2004 Tahoe Z71

[bandroidx]

I have a 2004 Tahoe Z71 4x4 5.3L and almost every day after it sits for the night i pull out of my parking spot, drive down the parking lot, and i always tap my breaks at the same spot and every day when i do this the first time oif the day it makes a weird noise coming from under my truck. Sounds like it comes from the middle.

The noise today got much louder and much longer in duration. It seems to always be when i tap the breaks for that first time after moving. it does NOT make the noise when i am pulling out of the parking spot.

Could this be an issue with ABS or an axle issue or something? I know this is not very much information to go on but i dont know what else to say to explain it. The pedal does not vibrate like ABS is engaging and the truck doesnt feel weird, its just the noise. its like a quick du-du-du-du-du noise, until today when it was much longer in duration.

thanks

 

[OR VietVet]

If it only happens when you apply the brakes for the first time of the day I would get the brakes inspected. This repetitive "du" noise happens only while moving and slowing down after applying the brakes, right? Brakes get cold after sitting overnight and the first apply of brakes is the first time you are starting to get heat in the brakes.

 

[bandroidx]

It doesnt sound like its coming from the brakes, it sounds like its coming from under the middle of the car. it happens when i touch the brakes, i just lightly tap them and the noise starts, even if i dont even try to slow down. my friend says maybe its ABS system because it starts up over 15mph or something, maybe its making a noise on initial testing:?:

 

[OR VietVet]

I would still check the brakes as I suggested to eliminate that possibility because it happens when you hit the brakes and your sense of direction of the noise can be effected by how noise travels. A video of the noise is also recommended. If not the brakes then check the drivelines.

 

[BeenChevy]

Does the noise go away when you shift into neutral while moving? If so it's likely your U-joints.

If the noise still exists rolling in N you can try and mount your cell phone or an audio recording device at each caliper for the short duration and hone in better. If your truck is lifted maybe duct tape the neighbor kid underneath while you cruise to try and figure it out.

 

[OR VietVet]

Some of those kids in the neighborhoods are getting wise to this and are demanding not only regular compensation but also demanding hazardous duty pay. I'm thinking they are getting unionized nation wide. Cheap listening devices, like the neighbor kid, are getting few and far between.

 

[BeenChevy]

my neighbors and i are repopulating the block.. we'll be set for the next decade or so.

 

[HiHoeSilver]

The ABS module is under the middle of the truck....

 

[1_8TTony]

Before you start the engine in the morning, get under the truck and hit the exhaust pipe on the drivers side.......hit it right upstream of the pipes first slip joint. You may be able to pin point the noise to the slip joint connection.

or.....

Start the engine and let it get up to normal operating temperature........After it's warmed up, hop in and drive your normal routine. If the noise is still there the first time you hit the brakes at that stop sign (with engine warmed up), I don't know what the problem could be. However, if the noise has gone away, I suggest you tighten the clamp on the exhaust pipe where the (drivers side) pipe first connects onto the rest of the exhaust system. I remedied this problem on a 2003 Escalade EXT. I couldnt tighten the clamp because the bolts were stripped so I ended up being lazy and instead of cutting off the old clamp, I installed a slightly larger clamp ontop of it and tighten it down. So far, so good.......been 2 or more years now.