The noise comes from the botton. It does not happens all the time, only in low rev and when engaged, D or R. It seems to come from the transmission or the botton of the engine.

Does anyone knows which TSB are available for the E53 4.8iS 2006?

Thx in advance!

Bottom of the engine is the oil pan then the bell housing of the tranny .... Try a heavier oil 10w-30 or 10w-40 and report back. Your metal skid plate bolts are nice and torqued to spec?

For clarification, When do you hear the noise when you rev the engine? Is it when the engine is increasing Revs, decreasing revs or only after the RPMs get back down below 2000 RPMs and after you have reved it up?

Were you able to use a metal bar or ratchet extension to pinpoint the location the sound is coming from?

You should be able to check if the noise is coming from the transmission by metal to metal on shifter shaft and to your ear, Check if the noise is louder or not. Try the same procedure at the back of the top of the engine. Not a sure thing but far easier than getting under the X. Worth a try

I will try a heavier oil, 10w40 next week.
The skid plate bolts are nice and torqued to specs, with no vibration.

Cold start, transmission in Por N: no noise.
Drivind (D or R) after cold start: no noise.
Warm motor, transmission in P or N: no noise
Warm motor, breaked, and transmission in D or R: noise
Warm motor driving, transmission in D, rev under 2000 RPM: mostly NO noise, but noise when climbing a ramp, a hill, or on heavy traffic.
Warm motor, in P or N, pressing accel over 2000 RPM and releasing accel: no noise on rev up, no noise on rev down, until idle, when noise brieffly appears. and then no noise.
Warm motor, idle, D or R, breaked: rev floats every 10 seconds, and when floating, noise appears.

So, i'm getting confused....

Does someone knows abou any TBS for the N62B48?

Thx in advance!

Warm motor, transmission in D breaked, noise, shafting to N, noise gone, shafting to R, noise, shafting to P no noise.
There is noise only when there is load to the motor, in low rev.

How many miles on the engine? How many miles on the current oil?

1)The easiest thing to do now is a metal ratchet extension or stethoscope that you can get from local auto parts store to your ear and to the engine. Can be anywhere in the front then the back of the engine on top even though the noise is coming from the bottom. If you can safely do the test on the bottom of the engine and transmission that's even better but not imperative. Then do the same check on the metal part of the shifter. The noise should be louder one place or another.

2) If no luck with that, change the oil as has been suggested as that is also easy to do.

You can also take the oil filler cap off and see if the noise is louder there. Does the speed of the noise stay or increase/decrease depending on RPMs.

Engine: 36350 miles
Current oil: 3603 miles