1999 chevy silverado 4.8L. clanging noise when accelerating, put in tranny, still got it, any ideas??

Question

i have had several mechanics look into this, the tranny did go out, but after a reman. still clanging. i have been told engine mounts, harmonic balancer etc. it seems to be due to torque, but it will occasionally make the noise at idle. sort of like the noise of a fan hitting a metal shroud, but more squeaky sounding along with the clang. we are stumped over this, any help appreciated

Answer 1

This sound like your problem....a way to tell .. Have some one slightly power jack your vehicle(in drive foot on brake and give some gas) around 1200 to 1800 rpm should get it going. once the noise starts ........step on the tail pipe.....if it stops this applies and is your cause.

Subject: Exhaust Vibration, Rattle,Resonance or Moan - keywords 4.8L 5.3L 6.0L A/C acceleration air conditioning fluctuation idle intermittent moan noise resonance rough vibration / rattle

Models: 2001-2006 Cadillac Escalade

2002-2006 Chevrolet Avalanche

1999-2006 Chevrolet Silverado

2000-2006 Chevrolet Suburban, Tahoe

1999-2006 GMC Sierra

2000-2006 GMC Yukon

2003-2006 HUMMER H2

Condition/Concern:
Some 1999-2006 C/K sport utility vehicles and trucks with GEN III V8 Engines and a single pipe exhaust system may exhibit an exhaust vibration that is engine load sensitive. Typically, this will happen just off of idle to 2000 RPM on light acceleration.

Recommendation/Instructions:

Obtain 4 dampeners, Part Number 10199232.
Line up 2 dampeners so the dampener pipes are opposite of each other.
Line up one mounting hole from each dampener with the holes of an appropriate size exhaust clamp.
With all of the holes lined up, weld the flat portion of the dampeners together and to the flat part of the exhaust clamp.
Attach the dampeners to the exhaust system using exhaust clamps and the following locations: On trucks with an 8 ft. bed, install one modified damper in front of the muffler and one just behind the muffler. On trucks with a six foot bed, install one modified damper in front of the muffler and one over the top of the rear axle. On Utility Vehicles, place one in front of the muffler and one anywhere between the muffler and rear axle bend. Fine tuning will most likely be necessary, especially on Utility Vehicles.


Basically add weights to your exhaust...

adding a flex pipe before your muffler will fix the exhaust rattle.and eliminate the need for the weights... any muffler shop can supply and install the flex pipe.

Answer 2

i like do it yourselfers. You human beings supply me loads of stable artwork on the dealership. All i will say is save up the stable artwork. We get excitement from your loss of understanding what your doing. My wager is you acquire 2 clowns who have not have been given any thought what they're doing, the two get the comparable 2 clowns to undo what they did or tow it to the dealership or restoration save & have them fix it

Answer 3

Did you look real close at flywheel,around area where it bolts on crank,might have a hair-line crack. just a guess.