When I start up my HDi (when engine is warm / hot) I get a boom boom
boom kind of knocking noise. The noise can only be heard from inside
the car yet it is driving as normal with no noises when on the move.

Unfortunatly the dealer doesn't seem to have a clue what it is and
had already had it in for 3 days and replaced an engine mount and the
camshaft pulley (thankfully under waranty) but the noise is still
there. Has anybody had a similar problem or can advise me on what it
could possibly be?

Cheers
Ramsay