[RocPile]

im hoping someone with a 2016-18 wrx can help answer this question of mine, but im open to any opinion really. So i have a stock 2017 wrx (automatic) that has been making a sound i am unfamiliar with.

when i am slowing down and passing 35-30km/hour, my car makes a quick whistle/chirp it might happen after my car has been in boost and i am trying to figure out why its happening. also sometimes when i am accelerating over 30-35km it will make that whistle/chirp sound again. now, this isnt a regular turbo sound im used to when it hits its peak and makes the "woosh" sound, or flutter type of sounds as my car is all stock.

a theory my friend had is the turbo is letting off a bit of pressure and thats the sound im getting, but it almost sounds like an older cars belt squeeking (mind you it only happens at that one speed and one very quick sound). does the stock wrx make any sounds like this normally? the tech at the dealership was saying it might be because of the wastegate, but he never did get to hear the sound as i couldnt Recreate it for him (figures).

now, if it is a normal sound, great. but i am trying to understand why it is happening. i feel like if i were to try and sell it that it would screw me over also. does anyone have the same vehicle that might be doing this? or have knowledge as to why its happening? im going to attach an audio clip, its myself making the sound, but its exactly what i hear...

 

[RocPile]

the audio wont attach for some reason

 

[4EverMetal]

Do you have an aftermarket CIA or OEM?

 

[RocPile]

thanks for the reply. i should of mentioned everything is completely stock. 5000km on the car but the sound has been happening since i got it at 30km

 

[rqjoe]

Didn't u ask this before? Have u tried slowing in neutral?

 

[XJman]

Your car shouldn't flutter as it's got a bypass valve. The flutter or choo choo choo is typically compressor stall. In your breif description it sounds to me like you are hearing the bpv and turbo whistle.

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[RocPile]

well its not a flutter. its a quick squeek/chirp. my friend has a STI and it does the regular sound of the turbo when he guns it. but myself, its making this sound when im slowing down over the 30km/hr mark. total opposite from when turbo's blow off. it just doesnt make sense why this is happening and the fact the dealership doesnt hear anything really doesn't help. as a stock wrx automatic, i will go from 0-80 gunning it and you migjt hear a little "pssshhhh" sound around 70km an hour or something when a regular turbo would sound. but i dont get why slowing down to 30-35km/hr it makes a quick chirp at that speed. noone seems to have an answer for me and i dont know why the audio clip wont attach to this post because it would help alot.

 

[XJman]

The turbo is entirely independent of vehicle speed it will change off of engine rpm.

What exact situation is causing this, gear, rpm, speed. Is it under engine braking, is it after going wot to closed throttle?

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[RocPile]

The turbo is entirely independent of vehicle speed it will change off of engine rpm.

What exact situation is causing this, gear, rpm, speed. Is it under engine braking, is it after going wot to closed throttle?

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honestly, its an automatic car so im not sure. speed is the only thing i can offer which is 30-35km/hour. anything you want me to check, ill gladly check. as far as the car and performance, i haven't seen a dip in RPMS or nothing on my boost guage seems irregular. everything is running smoothly. i couldnt tell you the gear as it only says D for drive

 

[rqjoe]

u still haven't said if you have shifted to neutral at a higher speed then coasted down past the 30-35km/hr mark to see if it does it in neutral...................

 

[XJman]

I'm nearly 100% positive he is hearing the belt in the CVT.

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[RocPile]

u still haven't said if you have shifted to neutral at a higher speed then coasted down past the 30-35km/hr mark to see if it does it in neutral...................

sorry just had a busy work week, i did it twice and it didnt make a sound but also a car drove by so that doesnt help. im free all weekend, ill make sure to test that out further.

annd as for the CVT belt, that could very well be it. it kind of makes that type of chirp/squeek, but only once. i have googled everywhere, and the only thing i can find is chirps with the manual clutch, or things on turbo flutter and havent seen a single thing related to my issue. hell, it may not even be an issue but its a sound i have never heard and same with everyone else i take for a drive. btw, if it was the CVT belts, would that sound mean its rubbing? or is that maybe the sound of it going from 2nd to 1st? car wont make the sound on idle with the hood popped.

and i apologize for redundent newbie questions hhaha its just what i am.

 

[RocPile]

u still haven't said if you have shifted to neutral at a higher speed then coasted down past the 30-35km/hr mark to see if it does it in neutral...................

alright, i have tried putting the car in neutral atleast 15 times, and not once did i hear that sound when slowing down. now, what could that potentially mean?

 

[XJman]

It means you are hearing the cvt

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[RocPile]

It means you are hearing the cvt

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really hey. a normal sound or something to still pursue with the dealership? just based on it being in neutral and not making that sound led you to believe that? sorry i really try to absorb everything i learn about vehicles

 

[XJman]

Should be alright. Unless it's really really loud.

A CVT has a chain or belt between two plates on the input and 2 on the output. As the "gears" change the belt slides up and down them differently. Google a CVT and how it works and you'll understand

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[RocPile]

alright thank you, i'll check things out!

 

[rqjoe]

I also have an Impreza and Forester with CVTs. I do not hear any such noise when slowing. Does seem to be the tranny, but I don't think it is normal.

 

[4EverMetal]

I'm soooo glad my car didn't come with a tranny, they crap me out!

 

[RocPile]

I'm soooo glad my car didn't come with a tranny, they crap me out!

hey keep your fear mongering outta this! hahahah