hi was wondering if any can help, i have a 2002 2.0 hdi 8 valve peugeot 307 sw estate

and the car doesn't appear to rev right, what happens is when you start the car up you can rev it straight up to 6000 rpm but after about 10 seconds the engine struggles to rev and seems to limit its self to 2500 rpm, the car has had all new filters and a complete service by a peugeot garage and they have also scanned the car with diagnostic machine and have nothing wrong, when the car limits its self if you keep the accelerator on the floor for roughly 1-2 mins it starts to smoke(blue and black) but it will clear and rev ok for a minute but the goes back into limit mode just wondered if any one had any ideas thanks mark