dumping sound with no dump valve

[mk4Martin]

At the mo i have no dump valve but i still get a dumping sound which is quite significant. a mate of mine said that this is the waste gate dumping . can anyone else here this ?

[ben_n_katie]

I had this, then All of a sudden I started having cold start problems which turned out to be the 2nd recirc valve.

[l4v15]

What car are you talking about? The mk4 1.8t 20v has a standard bosch plastic dump valve. Which recirculates the pressure rather than dumping it into the atmosphere, which is why you can hear it more with your windows closed through the dash. If you upgrade it to a decent one, upgrade your air filter or get your car remapped with higher boost pressure, you will here it much more. Standard plastic ones can sometimes leak boost pressure a little.

[samy_1800_turbo]

you want be able to hear the waste gate openin im sure the noise in your DV valve. do you have an induction kit coz the will make the dumping noise loader

[l4v15]

Hmm, maybe your talking about something else then

[RTechUK]

Is your car mapped? do you have induction kit / filter?

Is it a chatter sound or a whosh that your getting

I have heard blow off sounds with OME valves on remapped car running induction kits.  But if it has only just happened it could be a valve stuck open or a split vacume pipe or air box unclipped /slightley open?

If you want you can pop to me in Hinckley over weekend and borrow our VAGCOM to check all is ok. I can also pop my head under you bonnet and take a look for you.

[Maka]

I’ve over the past two weeks just started getting this whose sound, you can only hear it when I change up from 1st to 2nd, I’ve been in my local garage and they replaced my n75 valve I think, there are two of them at the top of the engine block, I had the right hand side one replaced, it didn’t make any difference, so there is a little plastic bit that looks like a spin top enclosed in rubber, they think its that making the whooshing noise, that’s £8 to replace. I’m hoping that will fix it. 

[mk4Martin]

thanks for all your replys .

i am driving a 1.8T remaped to 200ish piper cross panell filter . yeah i would say it chatters most the time but when i put my foot down and change gear i get quite a loud woosh . i am getting a new dv fitted tomorrow so hopefully this will make a difference

[RTechUK]

Hi!

That sounds about right then for a weak DV, if your running 200bhp then your held boost will be around 1bar nearly twice as much as standard, the chatter sound is the air in the positive side of the turbo coming back over the compressor blades  and echoing back up the inlet pipe more than likely the DV not allowing the +air to fully recirculate back to the induction side of the turbo.
 Same thing with all the other gears and the whoosh sound, but this time your have a greater volume of air coming back both ways.
 Once you get the DV sorted you should hear less chatter you should also feel less turbo lag, and find the turbo will spool up smoother and faster when shifting up the box. 
A 200bhp 1.8t Setup correct with that amount of volume of air at the remapped pressure you should notice it as a whoosh in all gears and not chatter. 

I am working at Lemington Spa Police Station in the morning so if you’re passing by and you see a blue new shape transit with the reg AC02NAS pull over... lol 

[mk4Martin]

will do mate if i am over that way. i quite like the dumping sound would i loose this then if i went to the forge 007p . this is whats making me consider the forge splitter. are they both as efficiant at their job?