Hello,

Drove my car fine yesterday, no problems. This morning the car ('89 745T) would go up in rpms and boost gauge would hit the yellow and I would hear a kind of loud hiss-sounding noise coming from vicinity of passenger side dash - presumably this sound is coming from the engine bay. The one turbo hose I never replaced was the little one that comes out of the turbo and goes into the metal pipe running into the intercooler input side. That little hose looks like crap and is actually kinda delaminating or something. So I replaced it with a cheap rubber plumbing connector hose that I picked up at Lowe's just to see if plugging a possible leak at that hose would cure a potential problem. No dice, still makes this sort of whooshing hiss sound that seems to increase and decrease with the amount of throttle you apply. When you ease off the throttle to get the boost gauge out of the yellow the hiss/whoosh seems to subside. Also, there are no obvious oil clouds, excess oil in hoses (other than the regular thin film), and the turbo shaft doesn't appear to have any abnormal play and blades are not contacting housing. Any suggestions before I start blindly purchasing new turbo hoses? Also the catalytic converter was replaced about 6 months ago and the car will get up to and cruise at highway speeds just fine, it just seems like the boost just is not getting into the engine or the gauge is lying.