Metallic sound when accelerating 2009 Tahoe

[kinglax08]

Hey guys I appreciate any suggestions and help with the issue in advance, but let me preface this by saying I looked at the simple things such are items in serpentine belt, fan, brakes, wheels, loose exhaust/manifold/shield, etc. No check engine lights.

Yesterday morning my 2009 Tahoe developed what I can best describe as a metallic rattle when accelerating; almost sounds like a bolt in a coffee can and much louder than a ping, piston slap, most knocks I've heard. No noise in neutral or park when revving the engine and no noise when in reverse and giving gas. I do not notice the noise when giving it a bit of gas on downhills until I really hammer down on the accelerator to pass or get up to speed. It also seems to hesitate a bit when accelerating. Oil looks fine. Transmission fluid looks good. I have not looked at transfer case fluid but plan on draining it this weekend to check for any big metal chunks.

Here is a video with the sound from inside the engine bay:

Any ideas what is wrong? My mind goes to flex plate, torque converter, transfer case, or worse yet bad transmission. Not driving it until I have a better idea of what's going on as to avoid any additional avoidable damage. Thanks again for any help!

2009 Tahoe 5.3l 4x4, 6 speed tranny, 150k miles, fluids checked and changed regularly.

 

[Doubeleive]

sounds like something smacking against a heat shield, I had a similar noise recently and it was the heat shield on the passenger side of the transmission rattling

 

[sumo]

Sounds like internals of one of the cats broke and just rattling inside. Is it more noticeable on drivers or passengers side?

 

[iamdub]

It doing it under load in gear points me to cracked flexplate, loose/missing crank bolt(s), etc.

 

[sumo]

You can pull the inspection cover and peak inside to see if you’re missing bolts or plate is cracked

 

[swathdiver]

Like Wes said, check all those little heat shields and as Chris and Ian mentioned check the torque converter bolts and flex plate. If a cat was that broken up it should have thrown a code but you never know!

 

[drakon543]

while your checking the exhaust heat shields check all the hangar locations too. had it happen to me once on a different vehicle. one of the hangars just popped out of the rubber which shifted the exhaust just enough it was bumping a piece of metal.

 

[gpracer1]

Sounds like a loose pulley.

 

[Doubeleive]

Hey guys I appreciate any suggestions and help with the issue in advance, but let me preface this by saying I looked at the simple things such are items in serpentine belt, fan, brakes, wheels, loose exhaust/manifold/shield, etc. No check engine lights.

Yesterday morning my 2009 Tahoe developed what I can best describe as a metallic rattle when accelerating; almost sounds like a bolt in a coffee can and much louder than a ping, piston slap, most knocks I've heard. No noise in neutral or park when revving the engine and no noise when in reverse and giving gas. I do not notice the noise when giving it a bit of gas on downhills until I really hammer down on the accelerator to pass or get up to speed. It also seems to hesitate a bit when accelerating. Oil looks fine. Transmission fluid looks good. I have not looked at transfer case fluid but plan on draining it this weekend to check for any big metal chunks.

Here is a video with the sound from inside the engine bay:

Any ideas what is wrong? My mind goes to flex plate, torque converter, transfer case, or worse yet bad transmission. Not driving it until I have a better idea of what's going on as to avoid any additional avoidable damage. Thanks again for any help!

2009 Tahoe 5.3l 4x4, 6 speed tranny, 150k miles, fluids checked and changed regularly.

aaahhh I was just trying to remember what else it could be also is the ac compressor, if you cant figure anything else out then try taking off the compressor belt and see if it goes away, I have had compressors make really weird noises before.

 

[sumo]

aaahhh I was just trying to remember what else it could be also is the ac compressor, if you cant figure anything else out then try taking off the compressor belt and see if it goes away, I have had compressors make really weird noises before.

Yea you could leave all the belts off. Then you’ll know if it’s a pulley or not. The ac belt though requires a stretch tool to reinstall. Might as well replace its

 

[Meccanoble]

Wouldnt any cat sounds or heat shield sounds be noticeable in neutral as in drive? The engine still moves and exhaust still flows. Pulley sounds that loud should show something strange in Park, after all, its right in front of engine and easy to see. I'm thinking hangers or something where movement of car would play a role.

 

[Alexquade]

I had a rock stuck in the heat shield of a Grand Prix I had. Made a similar noise, but it was random. Couldn’t duplicate it. One day I heard something fly off and the noise never came back. If you know someone with a GoPro, you could set it up in different and go for drives and see if it shows anything.

 

[RonnieMc]

Has anybody had a bad knock sensor or circuit problem? If it's happening under a load that could be valve ping due to detonation. Has it happened after filling the gas tank up? You may have gotten some bad gasoline ( low octane )

 

[drakon543]

ive had heat shields that would only rattle in drive or only at certain rpm ranges.

 

[njracer]

I have the same noise and I believe it's the starter gear not fully retracting. Google search "bell housing noise Chevrolet GMC 1999 Yukon". It's the same noise.

I have not had mine fixed yet but it's going in soon.

FWIW, I have a steep driveway and if I pull the truck in forward it rattles, pull it in backwards and nothing....which makes me believe when the ass of the truck is higher than the front, the starter gear does not hit the flywheel.

 

[S197Z06]

There is a ring around the driveshaft area. Had the same noise on my 07 . I just took it off. Had the same issue with another vehicle.

 

[njracer]

Just a very late update on this noise.

It was the starter and here is what was making the noise:

 

[dnt1010]

That is a Great followup. You know there are several owners out there just driving away for years with that noise LOL now they do not have an excuse since they know what it is. Fix It.............

 

[Idriveaho]

I bet that’s what I have going on. I can only hear it during slight accel like in the parking lot or drive thru.

 

[drakon543]

Just a very late update on this noise.

It was the starter and here is what was making the noise:

an update is better than no update. serious annoyance when your using that search function find a thread that is just what your looking for and nobody ever posted the fix.