Turbo noise - what's normal?

[AJP]

Hi

Had my GTI for a few weeks and there's something that's playing on my mind.

With the window down the turbo noise is quite noticable. Not in a bad way, it's not wailing or making any siren noises, just a 'ssss' hiss on boost. You can't hear this with the window up.

The DV doesn't chirp or flutter or hiss at all when I lift off.

The engine, intake and exhaust is standard.

It runs smoothly, and pulls well, although at times it seems a little inconsistent. For example once or twice when giving it full throttle from lower down the rev range, say 2500rpm, it doesn't seem to pull as hard through to the redline as if I planted the right foot from 3500/4000rpm.

I do intend to get it in soon for a rev G DV, PCV, and cam follower anyway, as it's safe to assume it may well be on its original parts.

I'm just curious what everyone else experiences with turbo noise, and whether what I've mentioned may indicate an issue.

Cheers! :-)

[Chris92]

I asked this when I got mine a couple of years ago and never really got a answer. Window down, foot down the sssssh noise is always there until you change up or let off the gas etc so basically always there when boosting. Since then I fitted a boost gauge and that peaks at around 13 and seems to hold around 10ish psi, I'm still fully stock minus the gauge and I still get the ssssh noise but from my research my boost reading seem to be correct so I just took it that the sssssssh noise is normal.

Best had be normal readings otherwise I've been driving around for two years missing out of some ponys, should also add that I've changed my DV but the old one was fine and the new one didn't change anything but atleast I know it's good.

[rich83]

Hard to say without hearing it "live". Get the new bits on and report back. The turbos on these do make some noise so thats nothing to worry about, but the inconsistent boost might be.

[AJP]

Cheers for the replies. 

Yes, the revised DV etc were on the to-do list before I even bought the car, as a result of doing lots of homework! So I'll get it booked in for that lot soon, probably at Statller up the road as they have a good rep.

Rich, the inconsistency is something I've noticed on other forced engines. Particularly a mapped AGU I used to run. But... I wondered then (and still do now) whether it was my mind playing tricks on itself - something to do with the harder kick when flooring it at mid revs rather than low revs making it seem like it pulls harder at high revs. Never noticed it with the old n/a valvers, but obviously a turbo changes characteristics of the torque delivery massively.

[Matthewsimone]

Mine sounded/behaved a bit like you describe when bought it
New rev G diverter davle and like a different car mate 

[jhook661]

I asked this when I got mine a couple of years ago and never really got a answer. Window down, foot down the sssssh noise is always there until you change up or let off the gas etc so basically always there when boosting. Since then I fitted a boost gauge and that peaks at around 13 and seems to hold around 10ish psi, I'm still fully stock minus the gauge and I still get the ssssh noise but from my research my boost reading seem to be correct so I just took it that the sssssssh noise is normal.

Best had be normal readings otherwise I've been driving around for two years missing out of some ponys, should also add that I've changed my DV but the old one was fine and the new one didn't change anything but atleast I know it's good.

your boost spikes at 13psi and holds at 10psi ?? mine spikes at 10-10.5 psi and held at 5-6 psi ?? standard
now I have revo stage one it spikes at 17-18 psi-ish and holds at 10psi that's impressive if yours is holding that kind of psi standard!

[Matthewsimone]

I asked this when I got mine a couple of years ago and never really got a answer. Window down, foot down the sssssh noise is always there until you change up or let off the gas etc so basically always there when boosting. Since then I fitted a boost gauge and that peaks at around 13 and seems to hold around 10ish psi, I'm still fully stock minus the gauge and I still get the ssssh noise but from my research my boost reading seem to be correct so I just took it that the sssssssh noise is normal.

Best had be normal readings otherwise I've been driving around for two years missing out of some ponys, should also add that I've changed my DV but the old one was fine and the new one didn't change anything but atleast I know it's good.

your boost spikes at 13psi and holds at 10psi ?? mine spikes at 10-10.5 psi and held at 5-6 psi ?? standard
now I have revo stage one it spikes at 17-18 psi-ish and holds at 10psi that's impressive if yours is holding that kind of psi standard!

Sounds like you have boost leak/seep somewhere mate, standard Gti runs around 12-13psi peak so drop off to 9-10 is completely normal
If your barely holding half your peak something deffinately isn't right!

[Kam88]

I got told edition 30 spikes at 12 and runs at 10 so few different opinions

[Matthewsimone]

Id imagine edition30 runs similar boost to standard Gti but obviously being a bigger turbo makes the extra power hence 227 bhp over the standard 197bhp

[dazza]

I got told edition 30 spikes at 12 and runs at 10 so few different opinions

I think this is wrong here is a log from my standard gti

[dazza]

Here is another log i took when i first got my car. (Torn DV valve.)

Someone asked the other day is it worth buying VCDS. I think yes from the log you can clearly see something is wrong.

[jhook661]

cheers chris92 for you info much help maybe I do have a leak somewhere my intercooler may have a little hole in it on intercooler hoses etc does any else know what everyone else what psi there running at stage 1 or standard ??

[Chris92]

cheers chris92 for you info much help maybe I do have a leak somewhere my intercooler may have a little hole in it on intercooler hoses etc does any else know what everyone else what psi there running at stage 1 or standard ??

No worries  the O-rings on the boost pipes into the inter cooler etc can leak, have a look there

[AJP]

Just updating this for the sake of reference for other forum users.

New rev G dv, pcv and cam follower fitted last week, and all is sorted. Boosts much harder and is less hissy. Can also hear the dv doing its job and making a little 'tss' when I lift off under load.