Alfa 159 Ti 2.4 JTD noisy tappets / valves
I've recently purchased a new 159 Ti 2.4 diesel, but am not entirely happy with the tappet / valve noise coming from the engine. Put aside the normal diesel sounds, this is a definite ticking noise from one side of the engine, when the engine is under load, and more pronounced when above 3000 RPM. It has only done 2000 miles, and has been back to the dealer twice with my concern. The dealer describes it as normal, but I've had many diesel vehicles, and none make this ticking noise (it has a metallic sound). I also feel that 26 MPG (around town) is low for a diesel.
I would appreciate anyones comments as to what they thought this may be.