9-5 2.2 TiD Auto - Sceeching

[chorister]

I bought a 9-5 2.2Tid Auto 4.5 months ago with a 2 year parts and labour warranty. I get a screeching (screech, screech, screech in about 1 second) at about 2,000 rpm, under gentle acceleration when the engine is hot and regardless of speed. It disappears if I lift my foot or put it down more firmly. It sounds metallic but opinions vary from leaking hoses, to waste gate sticking in turbo' and manifold leaks. The Turbocharger was changed under the warranty but the problem is still there. The garage I took it to seemed to expect me to self diagnose the problem. Has anybody else come across this problem and if so what was the solution?

Edited by chorister on Sunday 18th July 16:27