I have a 96 850 Turbo Wagon. During acceleration I can hear a loud "Whooshing" sound when the Turbo starts to boost. It's not a whine or normal turbo sound. It's a whoosh. (Purse your lips together as if you're going to whistle, and blow without making the actual whistle sound. That's the sound) I know, I know... My description is retarded, but I'm trying....It only happens while the turbo is producing boost. The boost needle climbs to halfway (12 o'clock) and then goes about one needle width into the white. I have replaced the BCS and the three vacuum lines coming from it. Any opinions? I have tried to check all of the major hoses into and out of the intercooler and could not find any leaks.....What is it??

 

Maybe one of the hoses are collapsing under boost.

 

You've got a boost leak for sure. With that description, I would take a close look at the throttle body hose. It's very common to get large cracks in this area over time, giving you little or no boost. - AB

 

I would love to see if rcarlborg solved his problem, as I have the same symptoms, without the whoosh.
I've checked all my vacuum lines, checked the bcu, checked the turbine fan actually spins freely, with minimal thrust or side to side play. No smoke, no bad turbo whirly noises. Just no boost. I was hoping to find the waste gate stuck in the open position, but thats not my luck.

 

Hi,

As others have suggested, do a good visual inspection. You never know, it could be as simple as loose/missing hose/pipe clamps.

Good luck,


JPN

 

Make sure the hose at the top of the intercooler isn't sucking shut under boost.