2001 Suburban 1000 RPM eng. vibration

paper_hunter_2

I feel a vibration coming from my loaded 2001 CT Suburban's at 1000-1200 RPM, other RPM values are smooth. Talking with two other 2000+2001 Suburban owners, they also continue to feel this vibration/roughness at these RPM values and are very unhappy as I.
I have heard two scenarios from two different dealers; Chevy tuned the 5.3 for torque and this is a by product due to a misdesigned rough spot on the crankshaft or cam. The second which I hope is the case is a misaligned heat shield.
Any 2000+2001 Suburban owners experience this ?

2000gmc

Paper_Hunter_2: My 2000 Suburban has a rough idle that is beyond "normal" limits. The dealer upgraded the software in my Powertrain Control Module (PCM) last time I took my vehicle in for another factory defect and the roughness did not improve. I was told by one bonehead service writer that the rough idle was due to a lean miss that all V8s have. If anyone else has a "fix" for this problem, please let me know. You can email me at bspencer@argingbull.com. I am taking my car in this Friday, 3/30/2001, for safety recall reasons and I will ask for the PCM revision to be checked/upgraded.

paper_hunter_2

2000gmc,

The idle (~600 PM) seems ok. but it's when you hit about 1000/1100RPM or 10-15MPH that you feel it. My dealer was able to reproduce it by putting it in gear, stepping on the brake, and raving the engine to 1000-1100 PM. They called it a drone noise and it was a characteristic of the vehical they said.
I told them I'm not in the habit of spending $38,000.00 for drone (noise) characteristics coming from my vehicals I purchase. So after a whole day at the garage they are ordering a new exhaust/muffler including weights (round doughnut looking things that may compensate for the vibration. Stay tuned......