[Issa.M]

I have a 2013 335i xdrive with around 75k miles. I modified the exhaust by doing a resonator delete and gutted the muffler. Ever since then there has been a rattling noise every time I cold start it (or at least I think it happened after the modification), it comes from the front right of the engine area. The rattling stops when the RPMs go down. I'm thinking it the wastegate from what I've read, but what would need to be changed? The whole thing or just some components? Also, is there a home fix I can do? It just happens when I first start the car other than that there is no noise.

Please let me know your thoughts.

[thejeremyman9]

Are you sure its a rattle and not just the sound from the WG opening fully on cold start? It becomes extremely loud and the tone changes once you delete the resonator and mod the muffler since all the high frequency comes through

[Issa.M]

Originally Posted by thejeremyman9

Are you sure its a rattle and not just the sound from the WG opening fully on cold start? It becomes extremely loud and the tone changes once you delete the resonator and mod the muffler since all the high frequency comes through

Sounds like it's opening and closing rapidly

[thejeremyman9]

Originally Posted by Issa.M

Sounds like it's opening and closing rapidly

Can you monitor/datalog? WGDC is a parameter, and you can see for yourself what its doing. 100% is full closed.