24 FL5 squealing when letting off accelerator

[optronix]

I thought multiple people reported that the electronic wastegate noise was on most turbo BMW engines as well?

This particular engine vibrates a lot. Especially in certain RPM ranges. They removed the balance shafts so this will be worse than any other 2.0L turbo Honda engine.

I’ve found the vibration is worse when the AC is on. Comfort mode makes it vibrate less through the pedal but that’s no fun!

I think I can correlate your A/C suggestion, I'll try to give that a shot... but my local climate with its stifling humidity means the A/C is definitely on more often than not. Comfort mode also makes sense- I spent almost 100% of the time over the winter driving this thing in Comfort mode maybe that's why I've noticed it more recently where I default to Individual more often, where I have the engine in Sport+.

As for other turbo engines, I've had my share, including BMW. I've had an N55 (e92 335i) and S55 (f82 m4) for long periods of time. Never noticed anything like this (the N55 made a lot of noises though...). I've also had the VAG 2.9L V6 in both an RS5 and a Macan GTS, 2.0L turbo in an Audi S3, 3.0L turbo in both an S4 and Macan S, 3.0L flat 6 turbo in a 991.2, and the 2.5L Turbo in a 718 GTS- no such noises.

So maybe there is another platform that makes this noise, but it definitely is not just "a modern turbo thing"...

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[007]

Interesting thread. While it may not be much help, since some have mentioned wastegate noises as a byproduct of turbocharged engines, I can confidently say it’s not common. I’ve had zero wastegate noises in my GRY and my M2C. None. This coming from someone who is meticulous about nvh and highly attuned to any sounds. Such noises would definitely drive me nuts.

 

[Giant Wonton]

I have this exact noise and it drives me nuts. I wish there was a fix. The dumbass dealership said it was a part of my aftermarket exhaust lmao.

 

[FL5Frank]

Normal my fk8 did it

now my fl5 does it

Makes car sound cheap ass he’ll but it’s the wastegate

 

[Cap]

I'd describe this more as a scraping noise vs. a squeal (if its the same thing I'm experiencing). At first I thought it was something stuck in the brakes but then I noticed it was every single time I'm off throttle. Sounds like crap.

 

[cryptolime]

i recognize that sound. that's the wastegate actuator and it's normal to sound like that. I hit the rev limiter pretty hard around 8k miles and it disappeared until i did the CRC IVD Turbo/Intake Valve Cleaner service at 14k miles.

 

[infiniteraiders]

I noticed a sound when I let off the gas as well.. I don't recall hearing this on my FK8. The only change I made was the K&N filter. I'll try to swap back to stock and see if it's still there.

Do you have any mods under the engine?

 

[jcm]

2025 fl5 700 miles, started noticing this "hissing" or "whistle" noise, while lifting engine breaking during downshift blipping gas moving to third and lifting off of gas although breaking makes the sound disappear faster likely due to moving through the rpm range that produces the noise faster during breaking, had me a little concerned about power train/possibly considered that this was normal break-in noises, does occur in 1-4th gear, strangely enough occurs less during initial warm up after a cold start, much more audible when engine breaking after warmed up and coming from decent load, don't have a microphone yet to observe more closely but it sounds like a lubrication related issue metal-on-metal or similar. anyone have any luck with a fix yet?

 

[lilDumpsterRat]

2025 fl5 700 miles, started noticing this "hissing" or "whistle" noise, while lifting engine breaking during downshift blipping gas moving to third and lifting off of gas although breaking makes the sound disappear faster likely due to moving through the rpm range that produces the noise faster during breaking, had me a little concerned about power train/possibly considered that this was normal break-in noises, does occur in 1-4th gear, strangely enough occurs less during initial warm up after a cold start, much more audible when engine breaking after warmed up and coming from decent load, don't have a microphone yet to observe more closely but it sounds like a lubrication related issue metal-on-metal or similar. anyone have any luck with a fix yet?

yes exactly, it worried me because I thought it was somethign in the transmission or lsd, so this high pitched metal on metal squealing sound is somehow related to the wastegate actuator? Why does the sound go away when you're not engine braking, or decellerating in gear off throttle.

 

[randica]

The Subaru I had prior to the FL5 made the same wastegate rattle. It's normal

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