1998 T4 Turbo "wooshing" under Boost

[bar72]

Hi all, got a 1998 S40 T4, been running fine for months, bought it in october and she was running sweet. First thing i did was strip out the airbox soundproofing and reinsert the stock panel filter. Recently installed a new pipercross filter which has increased the loudness of the wastegate chatter but this has nothing to do with my problem.

When i spool her up now i can hear a massive "whoosing" of air, assuming it's a boost leak but it's my first turbo'd car so don't really know what i'm looking for but i have checked the red / yellow / blue BCV hoses, upper lower charge pipes from intercooler and hoses from throttle body to turbo. Actuator arm is moving freely, but not excessive play, exhaust elbow to turbo nuts/studs are tight, can't find nothing, no splits or apparent holes that are visable to the eye. All jubilee clips are tight.

What i cannot work out is that i don't lose any boost at all, still as quick as ever.

All i can see is that the intercooler cooling fins, as in the vertical zig-zag fins that run between the horizontal fins that cool the air are damaged and slightly dislodged from the intercooler.

I have also noticed that the car / boost runs perfect when she reads "cold" on the info centre, only when she gets to about 50oC, the whooshing when under load / boosting starts is apparent.

As i don't know nothing about turbo's, any ideas as i can afford a rolling road the now [just taxed her & she's in for m.o.t the now]

Any help, suggestions would be appreciated

Barry

[The-Les]

Mine sounds the same but I thought it was normal. Check the brake servo pipe that slots into the inlet manifold, mine popped out once but that gave a loss of power. Little bit of liquid gasket will set it inplace fine and you'll still be able to remove it if needed.

[LiamT4]

Sounds like it could just be the panel filter.

Take it up to about 3.5k and let off the throttle, if it then sounds like its dumping the air then its nowt to worry about. A panel filter can give a sound a little bit similar to a dump valve when coming of the throttle, but quieter and a lower pitch.

[M-R-P]

Sounds like it could just be the panel filter.

Take it up to about 3.5k and let off the throttle, if it then sounds like its dumping the air then its nowt to worry about. A panel filter can give a sound a little bit similar to a dump valve when coming of the throttle, but quieter and a lower pitch.

Kinda like this but with a frantic four-pot note to it
[ame]http://www.youtube.com/watch?v=Tvb2vAJE3BM[/ame]

could be the hot oil in the turbo allowing it to spool better, giving the woosh when it's warm. Have you changed the oil recently?

[LiamT4]

I often found when giving people a lift, they would often ask "whats that whooshi noise" lol

Especially with my t4 that had the bmc induction kit on.

I miss induction noise

[M-R-P]

I often found when giving people a lift, they would often ask "whats that whooshi noise" lol

Especially with my t4 that had the bmc induction kit on.

I miss induction noise

You heard the latest one? I now have poly top mount, and turbo flutter...
[ame]http://www.youtube.com/watch?v=GAglHW1xT1I[/ame]

[LiamT4]

Stop trying to make me jealous. lol

I must get a silencer removed so i can actually hear my bloody engine.

[M-R-P]

Lol, I still have a completely standard zorst

[LiamT4]

Lol, I still have a completely standard zorst

Yes, but does it have 3 silencers and 2 cats?? Mine bloody well does!

[bar72]

thanks guys but it ain't wastegate chatter, here's a video of it so you can hear me spooling it in 3rd, starts at 00:09 in the video..

[ame]http://www.youtube.com/watch?v=v3qipt_VmC8[/ame]

[The-Les]

have you got a boost gauge?

[bar72]

have you got a boost gauge?

no, unfortunately, if i was to hook her up to laptop with ODBII cable and vol-fcr, would i get error codes relative to problem as EML is also on?

thanks

[The-Les]

I dont know much about error codes lol. did I see in another post you have a decat?

[bar72]

was decatted, had to stick stock cat back on for mot (

[The-Les]

dont you have to do something to the second sensor to fool the ECU with a decat? was it whoosing before you put the stock one back on?