I,m getting wine that sounds like a vaccum leak which comes and goes with the turbo. When the turbo kicks in the sound increases incrementally with the increase in boost. Cannot find a leak in any lines, any suggestions. Turbo is still performing and no loss in pickup.

Thanks Mike

I addition to what John listed you should also look at the bypass valve. It is the valve on the bracket forward of exhaust manifold. It is plumed into the turbo outlet hose and the turbo inlet hose. There is a gasket between the valve and the bracket that holds it and the bolts are notorious for loosening and letting the gasket go away.

My wife's 86 745T made that sound when the small line to the waste gate came off. The other problem was way too much boost. Check the line. If you have the Turbo+ kit, there will be a tee fitting in the line which connects to the Turbo+ solenoid valve mounted at the front of the air filter.