Car fluttering under power ! NEED HELP !

[tommy_d]

Hi everyone,

I have an 07 plate edition 30 on around 56K, I originally noticed this noise but now I have a revo intake fitted it is alot louder.

Basically when i put my foot down the car sounds all normal until the top of the rev range (3.5k +) when the DV valve starts fluttering alot and the car doesn't pull anywhere near like i think it should. It feels like i lose boost as such.

When i bought the car it already had a custom remap on the car and is pulling just over 300bhp.

I have checked my DV valve and i have a Rev C with no rips or tears in it, I have order a Rev D to see if this is the problem and i have also ordered a PCV delete as i was going to do this anyway.



Does anyone have any insight into this?

A couple of my mechanic friends have said it might be that the Rev C just wasnt able to hold the amount of boost that was being thrown at it.

[Pikey Motorsports]

Its regulating the boost all ed30 on standard boost control seem to do it on the stock boost control, around 3.5k sounds about right.. some maps more then others.. Your car would have always done it, just you can hear it now due to the open intake

The car shouldnt really feel like theres a high power loss though when you hear it, whos it mapped by?

[tommy_d]

It definitely feels like its over controlling and letting all the boost out because there is alot less pull.

As far as im aware it is a custom remap for CC tuning.

[bigmig95]

Any solution to this ?  mine is doing similar things.  Sometimes runs fine and pulls as normal.  But occasionally only at WOT it doesn't pull, distinct loss of power and I also get a quiet'ish fluttering sound, exhaust pitch does become louder when this issue arises at WOT.  Was thinking wastegate area / control due to the exhaust pitch change ?.  My Rev G DV is fine so I've eliminated that area.  If you have similar symptoms it's not normal. 

Let me know if you find anything.  I'll try and run some logs soon on mine and get to the bottom of it. 

[GrayMK5GTI]

You need a rev G DV pal, the D can leak boost, especially on a 300+bhp setup. TBH if your rev C is fine, I'd choose that over the D.

The K04 has been known to flutter, although a decent tuner (R-Tech) can setup the car to give a smooth flutterless power delivery 

[audiman]

The flutter is the turbo surging. Boost is being forced to come in hard too early. Basically the engine can't flow the air the turbo is trying to push through it. A tuner can reduce this by giving it a slightly laggy tune and then ramp the boost up.

Second reason could be a failing hpfp. If fuel pressure drops low the ecu will reduce boost. Then pressure will build and boost will rise again. This repeats and you can hear/feel a pulsing. You need vcds and check the hpfp requested and actual fuel pressures.

[tommy_d]

Hi all,

I have fitted the Rev D and it has actually made a difference the fluttering doesnt start sometimes and when it does it is alot higher up in the rev range.

I dont think there is a problem with anything else other than the map tbh, I am going to get a REVO map put on the car which im sure will fix this.

I do find the Rev D is alot better than the Rev C though, i chose a Rev D over a G because i like the no diagram approach personally.

[flashp]

I've had this, not found a solution so I'll be watching with interest here.....

In the meantime in case it's useful here's the thread I started: http://www.mk5golfgti.co.uk/forum/index.php/topic,73050.0.html

Driving technique can eliminate this. Pay attention to your throttle inputs in what gear and you can find a way to drive your car without this manifesting. Pulling from too low a gear with too few engine rpm's can lead to this happening for example.
Intakes do make all sorts of noises audible but they were always present.  

I would add that with this in mind if drive at say ~4000rpm and touch the throttle I get an instant solid push with no issues at all. These engines love to rev and are very good at sustaining power high into the rev range and their personality does change dramatically, particularly when tuned which can take some getting used to.