unskirted

Just approaching 850 miles on the car and just started noticing a high-pitched whistle coming from the rear. I can't make out whether it's from the turbo or the diff/transmission. Sound is a bit unusual from what I'm used too. Does anyone else experience this? Sound from the rear-view cameras are much more noticeable @ :24. Goes away once speed picks up

ara

I have something similar but I notice more when the rpms are coming down let's say to a stop. Wasn't there before and just showed up when it got colder. Is it because of the cold? I'm not sure but I am going to dealer tomorrow to get a tech to listen to this and change to summer tires.

ara

the rear view angle makes me realize it's the exact same noise. To me sounds like a transmission whirring noise. I also notice in manual mode let's say 70--80 mph cruising in 8th. If I tap the throttle the rpm jumps a few hundred before the "clutch catches"

unskirted

Please let me know what the shop says.

I’m going to check my older dash cam, but I don’t remember being there before. The noise looks like it sits between 2-3k regardless of rpm climbing or falling. Sounds like a jet turbine

ara

I will keep you updated, I didn't have this noise until maybe around 6000 km. I have very sensitive hearing. I notice details. And this just showed up out of nowhere but also it got cold here same time. Not sure if it plays a part. Where are you located,, is it cold at the moment?

unskirted

I'm in SoCal. Sounds like you might have a slipping clutch. How many miles on your car?
I have a 7-speed with 850 on the ODO, but I'll also try what you described at 70-80 mph

ara

I have about 8000 km on the car now, it only does so in the 8th gear. Any lower gear and any throttle input the car moves accordingly.

Fullyield

Turbo whistle as it spins up and down?

Fullyield

You have two small turbines on the rear of your car….one located on each side???

unskirted

please watch video with sound up first?? Does that sound like a turbo??

I haven’t found any other videos on YouTube with this sound

Fullyield

I listened to both before responding. Sorry I responded. Best wishes.

Jeahbladejeah

Just posted in another thread about this same thing.
https://rennlist.com/forums/992/1342...nd-manual.html

Quoting myself: I just purchased a C2GTS with 7MT yesterday and I noticed this noise on the test drive. The car does not have dash cams or any add-on electronics to my knowledge. The sound was very obvious to my ear, but as I recall only off-throttle and/or under decel and low RPM. It didn't sound 'out of place' to me with it being a first drive, but it also didn't sound worrisome.

I agree it doesn't sound like the turbos are making this noise. My first thought was something like negative boost pressure throwing off a weird sound somehow... intake maybe?? But then again it sounded more mechanical or tin-ey than a whistle. I will report back once I take delivery (next week can't come soon enough!) and I have a bit more seat-time with it.

Note: my car has the lightweight package, so there could be something that is normally not as noticeable with standard sound deadening. Curious that your dealer mentioned its a C4 issue and mine is RWD.


Edit: ^ some of that is out of context because it's from the other thread.

After listening to your video it's not only under decel, so that probably rules out negative boost pressure. Interested to hear what everyone's dealers say.

22992

Sounds like a turbo to me. Under decel they can make that noise. Attaching a video of a Cummins turbo that was modified by taking the silencer ring out, thus making the noise. It’s possible your turbo is on the edge of tolerance and is a bit more noisy than others.

https://m.youtube.com/watch?v=smiQxxZq-jM

reyesanders

Any update from OP? Was the sound diagnosed as normal? I hearing the same noise on my 23 C4S PDK since new.

jjw285

I had a similar whistle around 20-40 mph. Never figured it out, just learned to live with it.

Some said it was aero, side mirrors, windshield, etc. I never figured it out.