Originally Posted by
Bidja
It is not an exhaust manifold or failed gasket either side of turbo?
Different engine/turbo but my CRD produced a metallic squeal noise (like a fan blade against a metal cowl), at low revs/low boost(eng hot or cold). Took air induction pipe off turbo inlet and was certain it was coming from within turbo itself.
Sounded like the compressor wheel was scrapping side of housing, there was a bit of side slap of turbine shaft bearings and I could stop the squeal by reducing boost level at idle.
Replaced turbo and noise still there "bgrr mee", pulled down again and ended up being exhaust manifold gasket due to warped manifold. There was no exhaust gas wash evident at all.