OvO

I have a video of the sound right here. It happens when I put my foot down on the pedal hard, sounds like it's coming from the transmission, I've read that potentially changing the transmission fluid would yield a fix. Anyone have any more information on this or have had this happened to them before?

Vid:https://streamable.com/0hbl

Jack88

Is that what the famous A8 transmission hoot sounds like? I never actually heard it before. There is a TSB for it, TSB 2013023/9. It basically says the fix is to flush the transmission fluid and replace it with the new type, as well as a software update.

mishar

Listening to it over the boat engine in the middle of Aegean sea I would say it's the hoot. The cheapest way to get rid of it (temporarily) is refreshing ATF with ~6 liters of the same fluid. The right way is that TSB but it is quite expensive.

MP4.2+6.0

Yes sounds like hoot. What gear is it in when doing it? 3-4/4-3? That is the hoot TSB diagnostic. In a Jag XJ8 w/ same basic 6 speed ZF and a similar TSB, I also heard it in 5-6/6-5.

TSB here: http://uberlame.com/a6_tsb/Transmiss...ween%203-4.pdf As Misha mentioned, cheaper version may just be a fluid change with original spec fluid, assuming yours has "Gold" (ZF6) rather than already had the TSB work done. Two fluid changes needed to get to about 75-80% change level. First one only gets about 60%, IF you drop pan to change filter. Closer to only half if no pan drop.

OvO

Ah I see. Thanks for the conformation fellas!

I'll have to check what gear it does it in when I get home.

I also have noticed slight vibration noise when decelerating, accelerating at slow speeds, I'll post a vid below. Is this the shudder that they are mentioning in the TSB or unrelated you guys think?



Vid:https://streamable.com/l0vz

Panelhead

I have heard about "hoot" and did not expect that noise. My XJR makes a noise under hard acceleration that may be supercharger whine. I thought was hoot. But is high pitched and starts around 4000 rpm. It does not take long to go from 4000 to shift point once it gets wound up.