Zaddddy

Hi!

I have a 2019 c43 with a stage 1 AMR tune and recently I installed BMS intake . After installing I noticed at 30-50 km/h there is a weird grinding sound when my boost is up and right when I let go of the gas the spool of the turbo kicks in. If I don’t give gas you don’t hear the grinding sound. If I give gas you’ll hear the grinding sound before the spool. Is this normal after installing cold air intakes? Once I get past 70 km/h you don’t hear the grinding when I’m giving more gas. I can try to record it but has anyone had this weird sound after installing a BMS air intake ?

MaverickC43

There’s been lots of threads with “weird sounds”
try to get a recording and I bet there will be people able to give u an idea or point u in the right direction.
did u contact BMS?

sdhayuj

Hello folks, perhaps another person had this issue. Just introduced the admission on my 2012 N55 135i last week, and I think something sounds bizarre. Doesn't make any difference whether the vehicle is hot or cold. I get the sound while speeding up somewhat right at 2000 RPM or so as I fire up, and afterward dropping off at 2700 or something like that. Assuming I press harder or step on it, the sound disappears. Difficult to portray, however envision placing some rock in the lower part of a 5 gallon paint can and afterward kind of twirling that around on the base. Kind of an unpleasant empty sound. It's not the typical super seems like a whistle or turning sound.





snaptube vidmate

aRandomUsername

I have the same issue. Any update on yours?
I have the same tune and intake. I can confirm that the sounds is not from the tune as I heard it before flashing.

I'm pretty sure it's the intake but not sure why it would make that noise

MaverickC43

Another response I’ve seen from the intake companies, which makes sense as long as their products fit correctly, is that an air intake is not a mechanical mod, it simply lets the the car breathe better. I’m doing so it lets us hear all aspects of the car more. So they’re saying the car did that before but it was muffled by stock system and couldn’t be heard
now this makes me feel like I may have paid to much for it to not do much. Lol
But with twin turbos breathing is a big deal
Especially if tuned.
I may try the MW carbon fiber if I tune ( I’m sure I will if I keep the car)

sdrutledge

Pretty sure you are just hearing the wastegate flapper opening and closing to regulate exhaust gasses past the turbo. That's why when you go WOT, you don't hear it. The stock airbox did a great job of hiding this noise, but I've had two different intakes (CTS and MST) and they both don't hide the noise as well as the stock box.

MaverickC43

And I’d bet the MW fully enclosed system would be quieter than the aftermarket intakes with the open filters

if I ever get one ill record the difference with their open vs closed system