This is my first post - and may I say what a laugh it is reading the bulletin board! Makes my afternoons while away much more quickly ...

My question: I have a standard '97 turbo Catalunya. As the turbo spins up (approx 3k rpm) there is a sound much like someone blowing over a bottle top. (It's not a high pitched squeal like some other questions posed - it's the sort of pitch you get blowing over an empty milk bottle ... is that accurate enough?!)

It doesn't last long - disappears beyond 4k rpm. Obviously it's something to do with the air induction but beyond that I have no clue.

Should I be worrying about it? Any ideas what it could be? I don't seem to be able to simulate it hunched over the engine bay manually manipulating the throttle!

 

Sounds like a faulty blow off valve, both easy and fairly cheap to sort.



I'd go for a Forge recirculating one.

/J

 

Ravster,A faulty dump valve is described as making exactly the noise that you are hearing.

 

Have a look at SIDC "common problems" section:

"3.1 Dump Valves (aka Blow off Valves and By-pass Valves)
There seems to be a recognized problem with the 1997 specification car's dump valve. This does not shut properly under boost and thus vibrates giving the sound similar to someone blowing across the top of an open bottle. It has also been likened to a steam train whistle or ship fog horn in extreme circumstances!. Meanwhile the 1998 model seems to have a totally revamped and larger blow off system, but I have had reports that the problem sometimes still occurs."

Regards Jim

 

Thanks all, I will investigate getting a new spec blow-off valve.

 

Ravster,

I have a MY97 with exactly the same problem, if you don't mind me hijacking your post and adding a few more questions...

1/ Apart from the noise are there any other symtoms associated with this fault (i wouldn't know since i've had the prob since i've had the car)?

2/ Is this a warrantee change? (got a 1 year extended warrantee)

thanks

 

My MY97 WRX also has this problem, I can get the noise to happen only in 4th and 5th gear under light acceleration between 3 -4K rpm. My boost gauge also sometimes only reports .5bar and will not produce a proper 1.2 bar until the car has sat switched off for some time. Is this also related to the blow off valve?

Sorry also for hi jacking the thread.

 

Was a warranty repair when i had mine done ! if your warranty still covers it get it done ! if not fit a Forge or similar recirculating BOV ! its best not to use a vent to atmosphere one !!!!

 

Tis a duff dump valve.
Mine made the noise when I test drove it. Luckily I had read the SIDC site about common problems before looking for a Scoob.
Unfortunately the muppets who I bought it from had not.
They tried to test the problem in the garage, but it requires some load on the engine. You may notice that it happens earlier than 3000 rpm going up hill and v.v. on the other side.
I can't say I noticed it affected performance as I was only just getting used to the car, but booting the car hard caused the odd stutter for a fraction of a second.
It was a warranty job so no money worries.
The new one has been on for 10 months and I am again starting to get odd stuttering, so perhaps I will change to a recirc job that is up to the task.

Nick