[photoexpertlee]

BMW 420i (b48) from MAY 2018

50000 miles on the car

I've been hearing a rattling/ticking noise from the undercarriage
while accelerating lightly and driving at a low speed on flat road or on incline
at around 1000 to 1500 rpm


has anyone had this issue and knows how I might resolve it?

[cfm56d7b]

Very difficult to isolate the noise in the video. When did this noise first become more noticeable?

[Freddie_Rome]

Yes, on medium-high loads, under torque. I also noticed on mine, both stock/aftermarket exhaust

[photoexpertlee]

Originally Posted by cfm56d7b

Very difficult to isolate the noise in the video. When did this noise first become more noticeable?

there's 2 more videos for you !

17 sec ~

15 sec ~

[photoexpertlee]

Originally Posted by Freddie_Rome

Yes, on medium-high loads, under torque. I also noticed on mine, both stock/aftermarket exhaust

did you found any solution?

seems sound from mid pipe of exhaust or catalytic converter.

[Freddie_Rome]

Originally Posted by photoexpertlee

did you found any solution?

seems sound from mid pipe of exhaust or catalytic converter.

Unfortuntely no. I have aftermarket downpipe and exhaust and notihing changes. I would like to discover the solution too

[photoexpertlee]

Originally Posted by Freddie_Rome

Unfortuntely no. I have aftermarket downpipe and exhaust and notihing changes. I would like to discover the solution too

Oh... I thought it was a catalytic converter rattle or turbo wastegate rattle

now it seems like sounds are from wastegate

[Freddie_Rome]

Originally Posted by photoexpertlee

Oh... I thought it was a catalytic converter rattle or turbo wastegate rattle

now it seems like sounds are from wastegate

Yeah probably WG. We need a go pro camera in the engine bay

[domi1234]

hello
i hawe same noise on g20 330i but under acceleration at 3000 rpm and up
hawe you found a solution to this?

[Fyodor]

Hey its sound of the rear brake pipes they touching the cardan shaft and make the noise I had it on my f30 2016 the original bands that catch this pipes because of the hot weather in my country its dry and broken so I put it on a new band an its stoped make the noise

[mgi]

Hi there,

It's been a while since the original post and the follow-ups.

I have the same kind of noise, and the dealer isn't of much help. Has anyone managed to find the cause? Is it a problem, or I can write it off as 'normal'?

Thanks

[mgi]

Update: I went to a different dealer, and they said the noise is caused by the actuator mechanism for the vacuum capsule, which rattles. Apparently, it's normal and nothing to worry about. I guess time will tell

[Freddie_Rome]

Originally Posted by mgi

Update: I went to a different dealer, and they said the noise is caused by the actuator mechanism for the vacuum capsule, which rattles. Apparently, it's normal and nothing to worry about. I guess time will tell

Sorry, what is "vacuum capsule"?

[mgi]

Sorry, lost in translation

I was referring to the wastegate.

[davigar]

I have a similar sound in my F31 330i with 100.000 kms and think it´s the wastegate actuator.

To check if the sound comes from there, you can use an screwdriver (because it is to hot to touch with the fingers) to lock the play between the valve axle and the turbocharger body while a third person revs the engine. If the rattle sound dissapears or changes, that is your problem.

This is a common failure in past BMW turbo petrol engines, like 335i e9x and the solution is to drill and resold a new valve or replace the entire maniflow.

Here you have a video that explains the problem and replace the part.

Bye!

[Senhorcheeks435]

This was my problem Idk sounds like rattiling or something taking it in Tuesday wish me luck



https://youtu.be/JIIWBrxopf4