E88 135i N54 wastegate rattle + intermittent CEL, beginner trying to diagnose
I own a 2008 BMW E88 135i convertible (N54)
For the past few days I’ve noticed a weird metallic rattling/chattering sound at very low speeds/low RPM. After listening to examples online, it sounds a lot like wastegate rattle.
Since the rattling started, my check engine light has come on twice. Both times, the light stayed on until I parked the car, turned it off, and turned it back on. After restarting, the light disappeared and the car seemed to drive normally.
Other than the rattle and the brief check engine light, the car feels normal to drive.
I’ve heard people talk about putting washers somewhere to help fix the rattle, but I honestly don’t really know how to access the wastegates on the car. I’m completely new to working on cars like this, but I really want to learn and try to fix it myself instead of immediately taking it to a shop.
What would you guys recommend checking first? Also if anyone has good YouTube videos, diagrams, or beginner-friendly guides for diagnosing/fixing this stuff on an N54, I’d really appreciate it.