Turbo Flutter/Surge off throttle - DV solenoid?

[muff1991]

hi all, still chasing turbo flutter (as well as small rev hang) on my GTI. I cant figure out what it is... I'm now wondering if the solenoid on the DV isn't pulling the DV back when I lift off the throttle and that's what's causing the flutter? its such a pathetic flutter too.. I don't want it fluttering..! would of thought i'd get a code or something but nothing. holds boost ok.

its had a new Rev G and made no difference. I've checked all the obvious stuff.. but any ideas please shout out :)

I was wondering if there's a fuse for the solenoid or any other reasons what and why its fluttering. its done it since I brought the car but my last one didn't do it!

yes I have a Ram air intake... but I've said in a previous post.. my cousins and my mates GTI with the same intake doesn't make this fluttering noise.. they just get woosh at most.

any advise or a point will be great please.

[pudding]

I'm guessing it's mapped?  Fluttering during acceleration or only when letting off the gas?

[muff1991]

I'm guessing it's mapped?  Fluttering during acceleration or only when letting off the gas?

Hey Pudding, not mapped yet as want it perfect before doing so! Its fluttering as you lift off the throttle. you can sometimes hear it flutter then dv pshhh but the pshh is very faint the flutter is loud.

[pudding]

Yeah that's normal mate.  The factory airbox absorbs that sound.  It shouldn't be excessive though, just a couple of cha cha noises.  Maybe the DV isn't responding quickly enough.

[Dave aka]

Just to confirm he’s running nearly the same mods as my gti had a few years back and mine didn’t drive or sound nothing like his, power drops off like the Pcv or dv valve is broke but both have replaced, no real boost leak issues (well with the bayonets and standard intercooler on the gti’s that’s a lie lol) the car drops out of the power for roughly 2-2.5k on the revs then power returns immediately and pulls hard, it’s making a wooooo noise Not dv related like air is hissing out but no visible boost leaks anywhere, it’s not throwing a light on.......think its gonna have to be Vag com next mate start looking at measuring blocks........again 😎👍🏻

[muff1991]

in all fairness the noises etc. was all happening before i started experiencing power cuts. i understand what you're saying pudding.. but i find it hard to believe this to be the induction kit. as you said it shouldn't be excessive.. but in my opinion its very loud! Aka's BWA don't/didn't do it and nor does my mates! AXX (same setup as me - apart from i have a backbox delete? only difference)

I have a sound recording but don't know how to upload it??? (its not very good but will sound closer than my chirps... squeal... chatter words lol)

[pudding]

Sorry, should have been more clear.  The intake doesn't cause the noise, it just reveals/amplifies it.  Any changes in the exhaust and intake can affect how the turbo spools, but deleting the back box shouldn't affect things drastically.  If there's a big power drop, I think it's time to crack open the laptop and start logging the usual measuring blocks.  MAF, low and high pressure fuel pumps, lambda, boost pressure etc etc.

You can upload it to somewhere like flickr or photobucket and link to it in this thread.

[muff1991]

Sorry, should have been more clear.  The intake doesn't cause the noise, it just reveals/amplifies it.  Any changes in the exhaust and intake can affect how the turbo spools, but deleting the back box shouldn't affect things drastically.  If there's a big power drop, I think it's time to crack open the laptop and start logging the usual measuring blocks.  MAF, low and high pressure fuel pumps, lambda, boost pressure etc etc.

You can upload it to somewhere like flickr or photobucket and link to it in this thread.

Cheers pudding. I’ll get the sound clip added on here via one of those, just so you can hear what it sounds like. I would defo say it’s not the normal noises you’d expect to hear and if so it’s ridiculously amplified lol it’s almost like the DV valve isn’t opening to allow recirculation or something but the flutter is pathetic
After reading a few things I reckon the power loss problem at 4K might be down to the N75 valve. It’s like the car goes into soft limp mode for a second or 2 then works out what it needs to do then goes like stink right up past that! I know VCDS is probably the only way of telling truly. I want to invest after xmas 100%


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[Dave aka]

N276 valve you animal!!  and I’ve got a spare for you to try mate and any other sensor you need 😂😂😂 I literally feel like every part you ask for I’ve got as a spare.....water hose, clips, boost seals, nuts bolts, bushings let’s be honest mate I’ve a cars worth of spares even if it’s a leak from the cam chain cover lol I’ve got you covered bro, cracked manifold I’ve got a spare, turbos leaking you know what I’m gonna say 😂😂😂 I’ve got u covered bro 😎👍🏻
It’s just the diagnosis/finding the fault that will take the time.......the engine is solid it’s just a teething issue, at least it’s not clutch/csc related 😱😑
Anyway drop a cdl in it and then the noise will stop 100% only thing then screaming will be me in the passengers seat 😝

[muff1991]

N276 valve you animal!!  and I’ve got a spare for you to try mate and any other sensor you need I literally feel like every part you ask for I’ve got as a spare.....water hose, clips, boost seals, nuts bolts, bushings let’s be honest mate I’ve a cars worth of spares even if it’s a leak from the cam chain cover lol I’ve got you covered bro, cracked manifold I’ve got a spare, turbos leaking you know what I’m gonna say I’ve got u covered bro
It’s just the diagnosis/finding the fault that will take the time.......the engine is solid it’s just a teething issue, at least it’s not clutch/csc related
Anyway drop a cdl in it and then the noise will stop 100% only thing then screaming will be me in the passengers seat

Haha AKA you’re the man we’ll get it sorted one way or another


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[muff1991]

Sorry, should have been more clear.  The intake doesn't cause the noise, it just reveals/amplifies it.  Any changes in the exhaust and intake can affect how the turbo spools, but deleting the back box shouldn't affect things drastically.  If there's a big power drop, I think it's time to crack open the laptop and start logging the usual measuring blocks.  MAF, low and high pressure fuel pumps, lambda, boost pressure etc etc.

You can upload it to somewhere like flickr or photobucket and link to it in this thread.

https://vocaroo.com/i/s0tanvQSMInM

providing the link works, let me know what you all think this noise could be (its not the best sound clip but its close enough) different throttle position release at different rpm determines the noise. but what you're hearing is simply throttle release. I'm not tapping throttle again to cause this flutter/surge/chirping. let me know, thanks.

main chatter spoken about can be heard from 16 seconds.

[muff1991]

does anyone recognize the noise? it's doing my head in lol

https://vocaroo.com/i/s0tanvQSMInM

[mjmallia]

Sounds fine to me if a CAI is on.

[muff1991]

i just find it so hard to believe this to be the CAI when others don't do it 

[pudding]

Sounds normal to me mate.  It's just resonance in the drain pipe mate and nothing to worry about.  Just tell your mates your GTI sounds like a Bugatti Chiron 

The engine falling on it's face at 4K is a problem that needs looking into though.  You do need VCDS unfortunately as there are too many parameters to monitor at once, which is impossible to do on a phone with an app.