Strange Sound on Deceleration

[wootwoot]

I have recently noticed a strange sound that I experience at low speeds. When I am traveling at low speeds and let off the gas I hear a metallic sort of sound. Not really a grinding but something moving. I only hear this when letting off the gas below 20 mph. I was thinking maybe one of the brakes is scraping the wheel slightly but I am not sure what it is. Any thoughts?

[ringmaster2.0]

how many miles on the car?

[Patorious]

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.

[wootwoot]

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.

[mkunert]

Pop it out of gear next time, and see if you still hear it. At low speeds with the windows down you can often hear the brake rotors lightly rubbing on the pads. Makes a metallic sort of sound. If you then lightly touch your brakes, it will go away.

[jimrobbington]

I would bet on an exhaust adjustment if it is a rattling sort of sound.

[jordan345]

this is likely the flywheel.. i heard this upon deacceleration.. almost like gear noise. i first thought the clutch was going (i'm pushing APR stage 3 power on my b7 a4) but after replacing the clutch, the shop indicated they believed it was the fly wheel.. so this was all changed and i still have the noise, but to a lesser extent. the flywheel was super loose. the new flywheel still has a bit of noise, but i'm assured this is okay.

[wootwoot]

This noise does have a rotational sound to it if that makes sense. I will try popping it out of gear to see what happens. I have the tip so I assume you mean kicking it into neutral from a roll.

[mkunert]

Yes, just kick it into neutral. You are trying to isolate whether it's a drive train noise or engine noise. By popping it out of gear, if you still hear the noise, you know it's drive train. My guess if you still hear it, and lightly press the brakes, it will go away. If it doesn't go away in neutral, it's an engine issue, and I don't have a guess. jordan345's explanation would be as good as any I could come up with.

It shouldn't be a problem popping back into gear when you're rolling as long as you're not going too fast.

Edit** Sorry, you don't have a manual, so it can't be jordan345's explanation. Let me know what you find. I'm curious. And my old B5 had a horrible metal rotation noise that was the brakes. I learned to live with it.

[wootwoot]

mkunert I popped the car the car into neutral and the sound is still there. I tried tapping the brake and that didn't instantly kill the sound. The circular sound only goes for a few seconds after letting off the gas and it did the same thing this time. It almost sounds like something spinning down. I still can't tell where it is coming from either. The sound is pretty faint.

[mkunert]

Sounds like an engine issue and not a drive train issue. Can't tell what it is without hearing it. Try to get together with local AZers to see if they can help. If you're still under warranty, bring it in.

[CaSp3r9]

FINALLY after an hour of searching I found someone with the same problem as me! Did you ever figure out what was making the sound? It's driving me insane.

I have a 2006 2.0t 6MT, the rotational metallic-like clicking only occurs when decelerating (in all 6 gears) and when the revs are dropping if out of gear. When decelerating in gear, it takes 1.5 - 2 seconds for the noise to start - seemingly when the fuel injectors shut off. It goes away when I get back on the throttle. Could it be related to the low pressure fuel sensor?

Codes stored:
P2004 - Intake manifold runner control bank 1, intermittent
P0642 - Sensor voltage circuit A, low voltage
- - I'm told to check the manifold pressure/boost sensor(G31), Intake manifold position sensor(G336), Low pressure fuel sensor(G410), and ECM software version.

TIA

[pdub]

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

[wootwoot]

My problem ended up being a blown DV. I'm not sure if any codes were being thrown but I didn't have a CEL.

[dA4n600rr]

FINALLY after an hour of searching I found someone with the same problem as me! Did you ever figure out what was making the sound? It's driving me insane.

I have a 2006 2.0t 6MT, the rotational metallic-like clicking only occurs when decelerating (in all 6 gears) and when the revs are dropping if out of gear. When decelerating in gear, it takes 1.5 - 2 seconds for the noise to start - seemingly when the fuel injectors shut off. It goes away when I get back on the throttle. Could it be related to the low pressure fuel sensor?


TIA

I have the same noise. like a clicking.

[CaSp3r9]

Kinda like a card in spokes but higher pitched and more metallic sounding. It's weird. I'm banking on a fuxed dv cause that was woot's problem, our descriptions match and I'm flashed with APR so it makes sense...

[makav3li]

Its called turbo flutter, when the turbo spools down it can make that noise, almost like a metallic metal is barely hitting another metal portion faintly but quickly. I have it in my car too and it bugs me. I haven't heard much about it being bad, i've actually read thread where some people want that noise because they like it. I also have a blown DV in my car too, so I'll be swapping that out soon and hopefully itll fix it.

[pdub]

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.

[CaSp3r9]

Pretty sure we're talking about two different sounds, there's no way what I'm hearing is the turbo. And there's no way anyone could actually enjoy the sound, it's awful. I'm hard pressed to believe it's the dv but it needs to be replaced anyway so I guess we'll find out...

[quattro47]

Pretty sure we're talking about two different sounds, there's no way what I'm hearing is the turbo. And there's no way anyone could actually enjoy the sound, it's awful. I'm hard pressed to believe it's the dv but it needs to be replaced anyway so I guess we'll find out...

Believe I have the same issue, only when decelerating in every gear. always under 200 RMP. Its is pretty close to a card in spokes. Definitely sounds like something clicking and no way is it the turbo. Hear it everyday though. Almost like a rattle snake sound..kinda hah

[Sprode]

Its called turbo flutter, when the turbo spools down it can make that noise, almost like a metallic metal is barely hitting another metal portion faintly but quickly. I have it in my car too and it bugs me. I haven't heard much about it being bad, i've actually read thread where some people want that noise because they like it. I also have a blown DV in my car too, so I'll be swapping that out soon and hopefully itll fix it.

I think you are confusing the flutter for a different sound that some people want. A new DV will fix this problem tho.

[elwigglero]

Believe I have the same issue, only when decelerating in every gear. always under 200 RMP. Its is pretty close to a card in spokes. Definitely sounds like something clicking and no way is it the turbo. Hear it everyday though. Almost like a rattle snake sound..kinda hah

I have the same noise and the "D" revision of the DV. I'll update when I get time to try to troubleshoot.

[CaSp3r9]

I'm gonna throw in a Forge DV and pray that fixes the problem. I'll let you guys know when I do and the end result.

[quickaudi07]

I had the same problem.
It was my back brakes. The inside of the pad NOT THE OUTSIDE was cutting in the rotter and it was making metallic noise. I don't know if you have the same problem or not, It only takes a second to take your while off and take a look..

[elwigglero]

I had the same problem.
It was my back brakes. The inside of the pad NOT THE OUTSIDE was cutting in the rotter and it was making metallic noise. I don't know if you have the same problem or not, It only takes a second to take your while off and take a look..

That would make noise regardless of throttle input.

[CaSp3r9]

I still haven't had time to order a new Forge DV... elwigglero or makav3li - have either of you had time to troubleshoot and/or replace your DV? Any findings?

[makav3li]

Im currently deployed right now, but ill be home in about 3 weeks and will install mine then. I'm sure u'll have an answer by then tho, but from the sounds of it, I bet it will fix it, it makes sense.

[CaSp3r9]

Check this out... could be the problem.

http://www.youtube.com/watch?v=gzepU...e_gdata_player

[elwigglero]

Traveling for work next week, so I won't have time to look at this for a couple of weeks. I'm putting the car on a lift to do the snub mount at that time too, so I'll see if a buddy and I can narrow down the vibration. I'll update this thread if I find anything. I've had the noise for at least a year and performance doesn't seem to be affected, although the noise has definitely gotten a bit more pronounced since I first started hearing it.

[Homer]

Check this out... could be the problem.

http://www.youtube.com/watch?v=gzepU...e_gdata_player

On decel in overrun mode (Fuel injectors off) I really think that noise you and I hear has to do with the high pressure fuel pump being bypassed by a check valve.

[CaSp3r9]

Homer - makes sense as it does kind of have an electrical solenoid-type sound to it.

If anyone else has a chance to get their car up on a lift and see if they have any sort of play in their wastegate linkage as well I'd appreciate it.

[Homer]

Homer - makes sense as it does kind of have an electrical solenoid-type sound to it.

If anyone else has a chance to get their car up on a lift and see if they have any sort of play in their wastegate linkage as well I'd appreciate it.

I'm not sure check valve was the right term. More of a pressure relief valve. Anyway, the sound disappears at around 1750 rpm, which I assume is when the injectors come back on before the engine gets close to idle.
As smooth as this 4cyl is, I doubt its the wastegate rod rattling.

[CaSp3r9]

My sound cuts out at around 1400 rpm, which is also why I suspected it might be fueling related. I'm not ruling out the wastegate linkage though, as the rattling sound made when I push on it is all too familiar... I'm actually in the process of setting up my wireless inspection camera under the car and revving it to see if I can see any movement in the linkage. I'll let you know what I find.

[DRAKLORE]

I have very LOUD turbo flutter..... pretty sure its cause i have the wrong spring in my DV

[Homer]

My sound cuts out at around 1400 rpm, which is also why I suspected it might be fueling related. I'm not ruling out the wastegate linkage though, as the rattling sound made when I push on it is all too familiar... I'm actually in the process of setting up my wireless inspection camera under the car and revving it to see if I can see any movement in the linkage. I'll let you know what I find.

Yeah my 1750 was just a guesstimate. You might be right.

[CaSp3r9]

Set up the camera under my car yesterday and revved it to reproduce the awful clicking sound... I couldn't see any movement in the wastegate linkage but it was kind of hard to tell on the 2.5" screen. I'll try it again today or tomorrow and record the video this time. Making progress... I think... haha

[Sreddington]

Sounds like the problem I was having something in the wastegate was loose but didn't you say it happens when your in gear and out of gear?

[Homer]

It does it when the throttle plate is closed and the engine revs are decreasing, till about 1500 rpm. Neutral or in gear.

[CaSp3r9]

It does it when the throttle plate is closed and the engine revs are decreasing, till about 1500 rpm. Neutral or in gear.

EXACTLY how I would have said it. Glad to know we're at least on the same page and genuinely have the same problem.

[Aznkae]

could this be the noise you guys are referring to (listen carefully when the revs start to drop) I started getting it a few months back, I didnt notice it till I changed out my air filter and installed my 034 inlet pipe. At first I thought it was my DV, but you can hear towards the end of the video its coming more from around the turbo area. Plus I also had my DV replaced with the "D" vesion