High RPM 'rumble' back

[Davidonly]

Hi all. My E46 M3 SMG, 2004, 52k miles, has started to produce a rumble from under the floor seems like) as RPM reaches 6-7k. Its a much lower frequency than the engine is spinning at. Still a noticeable brrrrr noise within the cabin. I wonder if there is any possibility that engine mounts, diff mounts (bushes) or bushes in prop shaft could be going soft?

Anyone else had it? It more noticeable when car is heavy... I have an extended warranty with £100 excess so not too worried at present, but want to sort it out as it used to scream around to redline in all gears (well up to 3rd in uk).

Any ideas?

[shim]

mine has started the same but not RPM replated but speed related 65-80mph and over 100mph

not bad but noticable

doesnt matter what gear so its driveshaft thru to wheels, feels like left side but not def

[Davidonly]

Speed related sounds like wheel balance....? Also two resonnant frequencies defo suggests a balance issue.

Maybe I am imagining mine It sets in and gets more pronounced as revs hit maximum rather than being a resonnance.

Anyone? Good excuse to redline your cars a couple of times an let me know how they sound/feel... Mind you my own research yesterday consumend a fair bit of fuel!

[Davidonly]

Well folks I must be alone with my rumble

Fortunatley is was cured by Murketts in Huntingdon. It was the dual mass fly wheel, which was replaced with the clutch under warranty.

Much smoother now right round to red-line. Tho no as smooth as the courtesy car (a 116i) was.... Mind you there was a distinct lack of noticable progress in that! But very smooth to ride in.