On Friday evening coming home from work I noticed probably about twice the turbo whistle than usual. Thought it may have been the howling gales, but it wasn't.

It's still going fine and pulling full boost, it's just that I have to keep checking behind to make sure there isn't a pursuing police car with siren!!

Any thoughts or ideas please (it's a MY97 WRX STi3)

 

Sticking dump valve? Although that is supposed to sound like someone blowing over a bottle.

 

Until I completely de-cat'd mine (MY00), it always sounded like that, when hovering the throttle around turbo spool up, for the first week I woz looking nervously into my mirrors, I would swear to god there woz police

 

I hope someone will tell you that I am wrong but I had a turbo diesel car that developed the same noise when the turbo spooled every so often ( I know it is not the same as a scoob but it works on the same principle )

Anyway this happened for a month on and off untill one day under hard acceleration there was a pop a bang lots of smoke and a bill for a new turbo

 

Check the power steering fluid mate. When its empty it makes the howling noise as you described which is proportional in sound to the engine rev..

 

Ian.. Had to happen to you mate ! lol.

I had exactly the same noise on mine before i went decat..

Was kinda strange when i got it, but then i heard the same noise when out in another scoob. So, perfectly normal.

 

Thats alright Johnny, it was a company car. That means I got a new one

 

Sorry to jump on board here but I've an MY00 UK car and before I had the full de-cat zorst fitted I couldn't really hear the turbo at all. Now with the zorst I can really hear the turbo whistle as its spools up.

Is this good or bad? I can't quite work out which from the above posts

 

perfectly normal

 

From the replies so far it seems that some people have loud turbos anyway and that the noise is more apparent if the exhaust is changed or decated.

My worry is that it changed, literally, overnight. Could that be because the downpipe cat had decided to disintigrate? I know that it was not working effectivly anyway, but if it had broken up I presume I would hear the bits rattle. Still a little confused.

 

Turn your siren off!

Dom

 

madmoog

I can only go on my car and before I had the zorst the turbo whistle just wasn't there at all, nothing. Now I can hear the noise rise and fall as it spools up and down in traffic and not just when I boot it.

Do you mean the noise started a while after you fitted the zorst and not straight away? as for that I can't help you.

I do know that when I had a SS zorst on my 205 GTI and the baffles broke up it sounded like I had a dump valve with the bits flying around inside it.

 

EddScott,

I haven't changed the exhaust at all, as I said at the top it just started making more noise one day. Hence wondering if the cat was falling apart. Failing that maybe my hearing has just got better.
Confused now..

 

Sounds like the dump valve is slightly letting by,which can cause a whistle-if its stuck open further it sounds like blowing over a bottle.

[Edited by easyrider - 11/22/2003 5:13:51 PM]

 

Thanks easyrider, is there any easy way of checking that out?

 

You can remove it from the intercooler and try to blow through it, if any air does go through then that will be the problem.
Its also worth checking ALL pipes that are boost related(ie condition/connections).If there is a place for the boost to leak out of these you COULD get a whistling noise also.First check they are all tight.If any of them are perished in any way,or bulging,they will want replacing anyway.
Its allways worth eliminating the easy things before you look into it further-For instance, you hear quite often that when someones enging is running rough, and pumping out loads of oily smoke, they think its the turbo,and go and buy a new one for £600,when all they had to do was a compression test to find it was a holed piston.I know that example was a bit extreme compared to your problem--but they could have saved themselves £600!!

 

Madmoog

Sorry dude but those are exactly the symptoms mine had.
Took it apart and one of the impleller blades in the turbo was fractured.