Grinding noise just off idle (video inside)

[cobra]

Do you have the stock larger disk holes or the new mod smaller pump disk holes for the driving hub tabs?

I have the stock disc with drilled holes

[sapote]

I listen to the video again. Can you keep that grinding nose continuously by holding the rpm at certain value? In the video then rpm continued going up then down, and repeated and I think maybe you could keep the noise there by holding the rpm at that point. Or increase the rpm slowly to see if the noise behaves differently.

The rough noise sounds almost like the chain rubbing again the valve cover or something like that. It is not like hub driving tabs hitting pump disk hoses, nor vanos rattling (bad roller bearing). I think it is related to the chain moving and rubbing something the wrong way.

[cobra]

I listen to the video again. Can you keep that grinding nose continuously by holding the rpm at certain value? In the video then rpm continued going up then down, and repeated and I think maybe you could keep the noise there by holding the rpm at that point. Or increase the rpm slowly to see if the noise behaves differently.

The rough noise sounds almost like the chain rubbing again the valve cover or something like that. It is not like hub driving tabs hitting pump disk hoses, nor vanos rattling (bad roller bearing). I think it is related to the chain moving and rubbing something the wrong way.

I can only make it do the noise as I transition from idle to just-off-idle. If I rev to 1200 and hold it - no noise. At idle - no noise. Any other RPM - no noise. Because of that it's noticeable when starting from a stop and gentle raising the throttle like in city traffic. While driving there is no noise (other than the normal clackety S54).

It's a tricky one for sure! I am also thinking chain related.

[cobra]

Following up in case anyone else has this issue.

I compared another E46 M3 to mine and it also makes this noise. Slightly less noticeable, but definitely there and can be both heard and felt.

I can only assume this is some internal noises caused by the radial piston pump or vanos drive hub. It is kind of annoying now that I can hear it, but I am guessing it was there for the past 50,000 miles and I just never noticed it.