Strange Flappy sound

[joshgreensauce]

Hey guys,

I'm getting a strange almost flappy/chirpy sound. I can't hear it in the engine bay when I pop the hood it sounds closer to the middle of the car. Most noticeable when in gear (I'm dsg) but not applying gas. The entire exhaust sounded different since I had a new turbo installed. No codes, no performance issues. Just annoying as hell. Anyone have any hunch on what this could be?

Thanks!

 

[Hollywood0220]

Chirpy sounds are generally from bearings or air.
Given that you had another turbo installed, the DV might not be releasing quite enough and your turbo is slightly "surging".
If the sound is more toward the middle of the engine bay (up front); the only belt there is your Water Pump that is driven by the balance shaft. The bearings may be faulting out and causing the chirping noise.

 

[joshgreensauce]

Chirpy sounds are generally from bearings or air.
Given that you had another turbo installed, the DV might not be releasing quite enough and your turbo is slightly "surging".
If the sound is more toward the middle of the engine bay (up front); the only belt there is your Water Pump that is driven by the balance shaft. The bearings may be faulting out and causing the chirping noise.

I'd say it's like toward the middle of the car not really the engine bay. It's super difficult to identify to be honest. Im not sure what bearing there are that could be an issue or why the water pump would on seem to make that sound when in gear. In N it doesn't make the sound, at least not as audible. When applying gas it doesn't either or is way less audible. So strange. Seems to be worse after warming the car up and driving it for a second

 

[Hollywood0220]

Well, in that case is seems that you are creating NVH from a possible DP hanger / Exhaust hanger if it is toward the "middle" of the car and not the engine bay. Take a look at the hangers, that may be your problem?

 

[swcrow]

Most noticeable when in gear (I'm dsg) but not applying gas.

So you're hearing it while coasting in gear and not in boost?

 

[joshgreensauce]

Well, in that case is seems that you are creating NVH from a possible DP hanger / Exhaust hanger if it is toward the "middle" of the car and not the engine bay. Take a look at the hangers, that may be your problem?

Yeah I'll have to check under the car again but it looks clear. I know the bracket is tight that has the grommets but I removed the supporting brace from the engine bay area so that can't be it

 

[joshgreensauce]

So you're hearing it while coasting in gear and not in boost?

Yeah or just when stopped and idling in gear.

 

[Diggs24]

video

 

[joshgreensauce]

video

video

Yeah video doesn't capture the sound...I'll just keep an eye on it and report back if I get anywhere

 

[Hollywood0220]

Yeah video doesn't capture the sound...I'll just keep an eye on it and report back if I get anywhere

When you installed the turbo, did you have the clutch upgraded/worked on/seviced?
Maybe you are “low” on fluid?
Since it happens only in drive and worse when the engine is warmer, it could be an area.

 

[joshgreensauce]

When you installed the turbo, did you have the clutch upgraded/worked on/seviced?
Maybe you are “low” on fluid?
Since it happens only in drive and worse when the engine is warmer, it could be an area.

Great thought. I have the DSG and performed the DSG service myself only a couple thousand miles prior to the turbo install. With that, I am 100% sure the fluid level is at, or slightly above, the required spec.

I'm starting to think it is a slight exhaust leak, as my initial observation I have found to be false. I notice the sound in 'N' and 'P' but slightly less that when in gear. Really at a loss as to why it's making the sound it does - it is very difficult to film and in-person i can only describe it as around the exhaust area in the middle of the car. I'll get to it eventually when I get it on the lift for the downpipe swap for emissions, but am just driving as usual for now. Like I said, no impact to hitting boost, AFR's are solid, it's making great power, no fuel pressure drops, nothing. No smoke, no low fluids or leaks, nothing strange with the shifts or anything. Just a different sounding car since the turbo install and a slightly annoying tone like I said.

 

[Hollywood0220]

Darn Gremlins....

 

[jimlloyd40]

Great thought. I have the DSG and performed the DSG service myself only a couple thousand miles prior to the turbo install. With that, I am 100% sure the fluid level is at, or slightly above, the required spec.

I'm starting to think it is a slight exhaust leak, as my initial observation I have found to be false. I notice the sound in 'N' and 'P' but slightly less that when in gear. Really at a loss as to why it's making the sound it does - it is very difficult to film and in-person i can only describe it as around the exhaust area in the middle of the car. I'll get to it eventually when I get it on the lift for the downpipe swap for emissions, but am just driving as usual for now. Like I said, no impact to hitting boost, AFR's are solid, it's making great power, no fuel pressure drops, nothing. No smoke, no low fluids or leaks, nothing strange with the shifts or anything. Just a different sounding car since the turbo install and a slightly annoying tone like I said.

Is the exhaust touching a heat shield?

 

[joshgreensauce]

Is the exhaust touching a heat shield?

No and the bracket is also off. Maybe I have a loose bolt or so on the heat shield though...I'll have to double check that. I am fairly confident that all the clamps on the exhaust and the main bracket that has the grommets are all tight though. I'm also wondering if the metally film that is wrapped around some of the lines to/from the turbo are flapping or something.