6.0 Moan/Droan Between 1500-2000 RPM:
Engineering has investigated this condition and found the cause to be engine firing pulses causing the turbo mounts to vibrate/resonate. For trucks built through 9-29-03 install a revised turbo pedestal, P/N 3C3Z-6N639-BA. Trucks built after 9-29-03, install a turbo bracket A-brace, P/N 5C3Z-6N639-BA. If the droan is still present after installing the brace on trucks built from 9-30-03 through 1-17-05, replace the turbo pedestal with 5C3Z-6N639-AA. Ensure the droan is not caused by a bound exhaust system. Inspect for any damaged or broken exhaust hangers. Check the turbo downpipe by loosening the pipe at the top and bottom, checking its alignment and retightening. If the droan is still present, check the part number embossed on the turbo pedestal just below the turbo compressor outlet to the intercooler. If the number IS NOT 1846207C1, replace the pedestal with the above part. After replacement, or if the number IS 1846207C1, loosen the turbo inlet pipes and EGR cooler flange and neutralize by installing the components in this order: snug the flange between the LH and RH inlet pipes; torque the EGR cooler clamp to 53 in/lbs; torque the pedestal bolts to 23 ft/lbs; torque the turbo inlet clamp to 9 ft/lbs: snug the inlet pipes to manifolds. Ensure all components are properly aligned. Torque the flange between the LH and RH inlet pipes to 20 ft/lbs and the inlet pipes to the manifolds to 20 ft/lbs. Broadcast Message 0992, SSM 17530, TSB #04-9-4 & 05-19-12.




I noticed something like the description above. I can also feel a vibration in my accelerator pedal.
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Yep, I have it.

Just recently had my dealer do ALL of the above mentioned updates/procedures, (bracket/pedestal, etc)....and still have it :-(

I am beginning to think now it is purely related to my Turbo Back System, yet there is no binding, touching or other issues with it. It was there before the Turbo Back was installed, just can't remember if it was to the same degree.

Trying to learn to ignore it. Most don't hear it, BUT as usual once you notice something like that you focus on it ... GRRRRRR

 

I also have it...in a completely stock truck. I was talking to a buddy at work and he had a droan but it was caused by his 4" DP touching a cross member. He suggested i crawl under my truck and check my exhaust but i havnt gotten around to it yet. I doubt it is my exhaust though since i have stock exhaust. Maybe ill need to make a appointment at my dealership

 

Does the noise sound like a wine glass being rubbed with a wet finger? Sort of a harmonic sound? Mine has been doing it for some time and it seems worse on cold days,once the motor warms up it seems to go away. When the weather warms up a bit I will check all the above mentioned. After market exhaust may have come loose.