Strange Sound on Deceleration

[Homer]

Yep, that's the sound. Ironically I've been getting an intermittent p0299 code (underboost). This sound has been here since i've had the car, a year, perhaps the N75 is just on its way out and making that wastegate rod rattle.

[Aznkae]

Yep, that's the sound. Ironically I've been getting an intermittent p0299 code (underboost). This sound has been here since i've had the car, a year, perhaps the N75 is just on its way out and making that wastegate rod rattle.

I posted the vid on another thread and someone with the similar issue had his k03 replaced... hoping that not my case and I can just fix whatever it is. Whats/wheres the N75 valve??

[CaSp3r9]

Weird find of the week: I replaced my clutch switch and now the sound cuts out at around 1700-1800 rpm as opposed to 1300-1400 rpm. WTF mate?!

[Homer]

So the car finally threw a MIL with that same underboost code. Just dropped it off at the dealer. We'll see what they find. Perhaps it is the boost control solenoid making the wastegate rattle. Hrm.

[CaSp3r9]

This truly is the million dollar question. Rar!

[Homer]

Failed DV in my case. The noise is still there. Life goes on I spose.

[CaSp3r9]

I replaced my DV yesterday, noise is still there for me too. FML.

[Homer]

Oh hey, CEL came back on.

[CaSp3r9]

I'm 90% certain it's the wastegate linkage. I'm gonna try a temporary fix on it sometime soon to see if I can't get the noise to go away... if not, it's back to punching babies and drowning kittens.

[Homer]

Update guys. Went in for the 2nd CEL and they replaced the N75 valve.
Had the CEL come on AGAIN on monday took the car in and mentioned that clicking sound.
It turns out its a sticking wastegate actuator rod thats creating the underboost issue and the clicking sound. They are going to replace the whole turbo.
I feel like a bonehead for not saying anything earlier but then again they won't address an issue without a code.
Anyway, glad its finally going to be solved.

[Homer]

Got the car back. Boost issue and the clicking noise are gone. Thank god.

[Fermo]

The car has 35k miles. I haven't pinpointed where the sound is coming from because it isn't very loud. If I rev the car in neutral I do not hear the sound.

Did you ever figure out what this was???? I have this EXACT problem to a T!

[Fermo]

Update guys. Went in for the 2nd CEL and they replaced the N75 valve.
Had the CEL come on AGAIN on monday took the car in and mentioned that clicking sound.
It turns out its a sticking wastegate actuator rod thats creating the underboost issue and the clicking sound. They are going to replace the whole turbo.
I feel like a bonehead for not saying anything earlier but then again they won't address an issue without a code.
Anyway, glad its finally going to be solved.

So did fixing the N75 valve fix the clicking noise? I'm getting the clicking noise and if I can get a $75 replacement part to fix it I'd like to do that than replace the whole turbo!

[wootwoot]

Did you ever figure out what this was???? I have this EXACT problem to a T!

It was a busted DV. As soon as it was replaced everything was fixed.

[Fermo]

Man, I just upgraded my diverter valve like 30k miles ago, that sucks that its out again. Did you replace your N75 valve too?

[wootwoot]

I didn't touch the N75 valve.

[doublezero30]

Does it sound like a bike sprocket? Or a card in spokes?

i get the "card in spokes" sound when rolling under 20mph...what is that? 85k miles

[B8-A4]

lol so you dont have to read the thread, the sound is due to either a bad n75 valve, or the busted diverter, also the DV valve actuator could be getting stuck, which would end up being a turbo replacement.

i get the "card in spokes" sound when rolling under 20mph...what is that? 85k miles

[Homer]

lol so you dont have to read the thread, the sound is due to either a bad n75 valve, or the busted diverter, also the DV valve actuator could be getting stuck, which would end up being a turbo replacement.

Or the wastegate actuator arm being sticky. That's what ended up being the problem on mine. I've put on ~ 50k miles in the past 2 years on the new turbo. No issues since the dealer replaced the turbo.

[quickaudi07]

Sounds like I need a new tur o soon as well. I got a code yesterday P0299 I made a video of it as well..

https://www.youtube.com/watch?v=SNJA...e_gdata_player

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[Joshua Frye]

hello, i have a 2005.5 manual.. i have the bike sprocket noise.. what is the problem?! no codes but it drives me crazy!

[gyroscope]

I have the same problem and the dealership told me it's "turbulence in the intake". I don't know if it's because of a bad DV or what but I've been listening to this clicking noise spool down even before I chipped my car.

I think thats exactly what it is.

I started experiencing this same noise after I took apart the intake to clean it and change the filter. Sound has been there ever since.

[80sGuy]

Mine sounded like a DC motor spinning when I let off the accelerator pedal, very low and faint whirring type of sound around the 40mph range. As soon as I give it gas, the sound goes away.

[jnorman2]

Wastegate flap on your turbo.

Edit: I'm an idiot and didn't check the date first...

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[fel0ncod3]

Welp, looks like I’ll be joining the list of folks that this problem has puzzled.

Here’s a link to the sound I have. https://youtube.com/shorts/jQMWs6QhFZQ?feature=share

Have done the research and initially noted the noise on deceleration while driving. Then I figured, let me see if the sound happens while the car isn’t moving (to rule out the brakes and CV joint and a few other suggestions from people)

I’m thinking it may be time for a new turbo? Will need to find time so I can put the car on a ramp and have a look from underneath….

This is a 2010 B8 A4, 6 speed manual Quattro. It’s APR Stage 1, and ever since I had it flashed- car has been giving me a bunch of issues….

[Formula-R]

I'd check the driveline, I had a sound that happened which turned out to be a stone stuck in-between the heat shield and the axle

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[Kelvinben5087]

Check the exhaust hangers, especially if you notice it at a certain rpm. Sometimes at certain RPM it will resonate causing a rattle sound, cheap weld will fix if thats it.


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