Intermittent noise 640D gran coupe

[Jay928S4GT]

Hello everyone, my first post. Had my used approved GC6 a few months from a BMW dealer. Its a 2016 with only 25K on the clock. From cold, in normal/eco drive train, I get this intermittent noise/vibration at standstill and in 'd', with the brake held down as you would before moving off. Its felt at the brake paddle- then transverses across the dash. Noise lasts for 3secs then goes way. Notably, the RPM twitches ever so slight. The noise is not present when
set to 'sports' and I guess, switching to higher RPM you don't feel it as much. Nonetheless, it should not happen regardless of the mode its in.

As its still under warranty dealer found no fault codes, suspected the engine mounts and replaced both for piece of mind however, problem still persists.

I have owned many Bimmers (from std to high performance, new & old) and this one has me stumped!! Thought I'd turn to the enthusiasts for some real advise?

[easty027]

not experienced it with mine but i've seen posts about it. Could it be the engine silent blocks? not sure how they differ from the engine mounts if i'm being honest though?

https://www.6post.com/forums/showthread.php?t=1425241

[Jay928S4GT]

Originally Posted by easty027

not experienced it with mine but i've seen posts about it. Could it be the engine silent blocks? not sure how they differ from the engine mounts if i'm being honest though?

https://www.6post.com/forums/showthread.php?t=1425241

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Thanks for getting back. Not sure about that as and I would have thought dealer would swap them as they did the engine mounts - but we know they will take it in steps. I'm leaning more towards the Torque converter as this is the only mechanical component moving (with exception the engine running of course). However still puzzled why it Sounds perfectly fine when in Sports!! The techs out here should be able to point me in the right direction.