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Model specific boards => Golf mk4 => Topic started by: lilnickgti on 25 February 2014, 07:42

Title: Hissing under boost
Post by: lilnickgti on 25 February 2014, 07:42
hi wondering if anyone can help with this its really annoying..
Whenever im accelerating from 2k upwards but more noticiable between 2k-3k
There is a hiss coming from the engine area on the passenger side, i can only hear it with the windows up.
Doesnt happen when im parked up revving the engine only under boost when moving.
seems to be getting louder too, have checked all the pipes around the dv valve and seems to be no splits, but i think my  dv valve is knackered anyway, as the turbo flutters quite badly. 
Would the faulty dv hiss under boost does anyone know.?
cheers guys.

Title: Re: Hissing under boost
Post by: davidgtrr34 on 25 February 2014, 20:10
I had the same problem and it was injector seals
Title: Re: Hissing under boost
Post by: lilnickgti on 26 February 2014, 07:05
hiya mate, was that just on boost too and not stationary yeah?
Am going to change the dv on the weekend as the flutter is scaring me now, ive read on here that its not good for the turbo and dont really wanna be buying a turbo atm..
But also noticed today that i have a humming above 40mph :(
Title: Re: Hissing under boost
Post by: Nino on 26 February 2014, 07:59
Sounds like turbo spool to me, isit like pssssssssssshhhhhhHHHHHHHHHHH until you change gear? If its turbo spool it should start around 2kish and get louder upto about 3-4k then die off abit. If it is then thats normal and will get louder if you fit an induction kit and bigger TIP (Turbo inlet pipe)
The DV flutter is normal to a tiny degree depending on the Dv your using i have a forge 007p with yellow spring and upgraded piston and i get a tiny flutter which at first scared me but after having it checked I was assured its normal.

As for the humming at 40 sounds like a wheel bearing to me pal.
Title: Re: Hissing under boost
Post by: daz veedub on 26 February 2014, 13:44
Do you have an induction filter fitted ?
Title: Re: Hissing under boost
Post by: lilnickgti on 26 February 2014, 20:21
yeah mate ive got k&n, just a cone filter on the end of the maf..  I was thinkin its just the turbo spool but didnt notice it when I first got the car 6 months ago.. but if I open window I carnt here it.
yeah am thinking wheel bearing too but I think my front left calliper is sticking.. would that make a hummin noise when at speed..
cheers guys
Title: Re: Hissing under boost
Post by: lilnickgti on 26 February 2014, 20:24
oh yeah nino its a standard dv I think the factory original so could probably do with a change
Title: Re: Hissing under boost
Post by: lilnickgti on 01 March 2014, 21:01
Jacked the car up today and theres play on the front right wheel, at the 12-6 position i can rock the wheel slightly while on the other wheel its solid, so is that a wheel bearing failed guys??
Title: Re: Hissing under boost
Post by: northeast_gti-t on 01 March 2014, 21:27
Jacked the car up today and theres play on the front right wheel, at the 12-6 position i can rock the wheel slightly while on the other wheel its solid, so is that a wheel bearing failed guys??
Yes indeed that's a sign of a failing wheel bearing should be very minimal freeplay at that position will have a small degree of freeplay due to bearing preload etc but anything significantly more than the normal is a worn bearing plus with a hum above 40 mph indicates a worn bearing
Title: Re: Hissing under boost
Post by: lilnickgti on 02 March 2014, 07:44
cheers bud, ill get that done this week... it is just slight play but the drivers side doesnt budge like this one so ill change it..
so my hissining problem still worying me.. going to change the dv valve this week also hopefully get rid of my hissing on boost.. dont think its a boost leak coz am not losing any power and my car flutters an awful lot so hopefully dv valve fixes that..
Title: Re: Hissing under boost
Post by: Nino on 02 March 2014, 09:54
If you come down south wales id be happy to scan your car/have a look for you.
Title: Re: Hissing under boost
Post by: viperjsy on 03 March 2014, 10:34
can u hear the dv dump with windows up
Title: Re: Hissing under boost
Post by: WadGTI on 03 March 2014, 10:36
Get someone to record whilst your driving it and stick a video up on youtube :)
Title: Re: Hissing under boost
Post by: lilnickgti on 04 March 2014, 06:59
yeah can hear the dv flutter from inside with the windows up yeah, ill make a video today of the dv fluttering, and ill try n record the hiss but its not very loud so might not hear it on camera
cheers