X4 F26 (RHD) - Mystery Front Passenger Side Rattle at Low RPM?
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Hi all,
I’ve been chasing a strange rattling/vibration issue on my 2015 RHD BMW X4 F26 and wondered if anyone with an F-gen BMW has had something similar.
The noise is coming from the front passenger side (UK car), and it mainly happens:
• at low speeds
• under light load / climbing hills
• at low RPM
It’s NOT present:
• while idling
• at higher speeds
• under harder acceleration
Multiple independent shops have confirmed it doesn’t seem to be engine related, but nobody has been able to pinpoint it yet.
The rattling sounds like it’s coming from somewhere behind the dashboard air vents or above/behind the wheel well area on the passenger side. I checked under the bonnet for anything loose but couldn’t find anything obvious.
The sound is more of a metallic/plastic resonance than a knock. I noticed that it doesn't vibrate as much when hard turning right compared to the left so I'm thinking it could be something vibrating against the side panel of the engine bay that gets pushed against it (and thus no noise) when turning hard.
Has anyone experienced anything similar on an F26 or other F-generation BMWs?
Would appreciate any ideas before I keep throwing diagnostic money at it.
Thanks!