Hissing sound when accelerating

[colej]

Hi

This question may have been answered before, as found some threads concerning it on the a4 forum but nothing on the a3 forum.

Just bought a 2001 audi a3 1.9Tdi and have noticed when accelerating it makes a hissing sound. This is audible when you have the window down. It seems to happens at low rpm (about 1500-2500), it does not seem to happen when idling or when just revving the engine. Is it meant to make this noise?

Any help would be appreciated. Thanks

 

[sulaiman]

Sounds like the turbo boosting which you should be very happy of. lol

 

[MIKE GTR]

I know this sound, i had it on mine, it sounds like air escaping. Do the normal checks on all boost pipes etc - I could never find mine

 

[kitpayne]

I had a 1.9tdi passat which made the same noise. it ended up being a straight piece of rubber pipe near the turbo somewhere. not sure which pipe though!!

 

[jdas03]

I get that on mine all the time presume just the turbo, since i have owned thr car its made that hissing noise

 

[martin1]

well i don't know about anyone but i like this hissing sound

 

[Welly]

It's got boost leak written all over it.....

 

[lee111s]

Are you sure it's not just the turbo sucky noise

 

[Welly]

That's not really a hiss though, more of a whine....

Bottom line here is that the facts are a bit sparse!

 

[sportstractor]

any major leak will be quite obvious on performance and MPG.

Boost leaks aare a ******** fiind, just a massive process of elimination. I took mine for a smoke test and they found a little leak, still managed to find another leak afterward.

 

[Welly]

Tell me about it, I'm still hunting them down at the moment, after fitting the intercooler 2 months ago!

 

[gewagon]

Hi I have an Audi 1.9tdi 05 driving it the other day heard a slight pop and then the turbo has a loud whining/hissing noise , when I took of the wastegate acuator pipe (vacume) the noise stopped but lack of turbo power when I put the pipe back on I had full turbo power but the whining turbo spinning noise like the wastegate is constantly open , could this be the N75 Solinoid valve or an air leak somewhere I dont think the turbo is at fault as it is not rumbling or rattleling or like a bearing whine just the spinning noise of the turbo ?

 

[Dazboss]

Mine does the same :-s

 

[jwb7]

Hi
Just got an A4 1.9 tdi 98 s plate and i too have this ****** anoying high pitched whining noise, and when I remove the small pipe from the vacuum unit it stops, anybody replaced this N75 valve there talking about and did it stop the noise? I have checked the turbo fan and there doesn't seem to be any free play or looseness there

 

[gewagon]

anybody have any idea what this problem is ?

 

[Mr.Blonde]

Whats the smoke test??...

 

[shanejess]

if your tyre is now flat it was a puncture nothing to worry about.

 

[jwb7]

Took my A4 to an Audi mechanic yesterday and he says it's normal turbo noise,, well pleased as I thought major expense on the way