4200GT knocking noise when engine cold
| 30 June 2010
On all 4200GT and Gransport models a knocking noise occurs when the engine is cold and you pull off, although this sounds very serious, as though big end shells or something like that. The noise disappears when the engine is warm and that is an important point.
The noise is the exhaust manifold, as they double skinned and the inner skin breaks, knocking against the outer skin, but as they heat up the inner skin expands and gets wedged in place against the outer skin. Thus the noise disappears when hot but bad when cold.
I must emphasize this concern may not be the exact fault on your car and is for guidance only. We accept no responsibity for misdiagnosis.
