[tobysy_]

Hi all,

I’ve got a 2009 BMW 3 Series (E90) 320i with the BMW N43 engine (auto, ~47,800 miles) and I’m trying to track down a metallic rattle.

Symptoms:

- Metallic / chain-like buzzing around ~1100 RPM

- Much more noticeable when the car is tilted (e.g., on a hill)

- Happens in both Neutral and Drive

- Occurs more often under load when driving uphill

If I rev past ~1200 RPM it disappears

Occasionally a brief rattle again near 6–7k RPM

If the car is level it’s much harder to reproduce

It sounds like a metal-on-metal / chain-type noise, but since it’s dependent on the car being tilted I’m wondering if it could be something like a heat shield, exhaust contact, or engine mount movement.

Here is a video of the noise: https://youtube.com/shorts/hDowq1-fNSM

Has anyone with an E90 or N43 experienced something similar?

Thanks!

[TunafishE93]

I would say muffler/heat shield, rattling.