2005 Freelander 2.0TD4

I have a 2005 diesel freelander and I am an experiencing a very nasty metal noise when running it first thing in the morning.

This fault has suddenly developed when the engine goes over 2000rpm along with very jaulty power (kangaroo style).

After about twenty minutes this problem dissapears.

Any ideas what could be wrong?

Thanks

how long since it had an oil change ? thinking oil starvation to the turbo, till the engine gets really warm and the oil is then thinnest and would flow around the engine.