33cd smoky

hi, im new to this forum so hope im on the right track, i have a 330cd coupe diesel which had a water damaged engine so i bought a complete engine, turbo gearbox and turbo out of a accident damaged car with 52k miles, it runs great in till you give it a bit of welly then it starts smoking bad, i got the turbo off the blown engine rebuilt and fitted last weekend and it is just the same, i put an oil pressure gauge on it and it is reading 5.5 bar at 3k revs which iv been told is far too high, iv changed the oil pump and the breather filter in the rocker cover, tried it with oil cap off and its just the same, any ideas where the oil pressure relief valve is on these engines, also i can only get about 30mpg driving very cautious. forgot to say it is oil its burning and not diesel or water.

Is it smoking out of the oil cap an crank case breather an no smoke out of dip stick if so I have same problem iv had a new turbo injectors an injector rail air mass meter an still the same cheers ant

no, mine is smoking from the exhaust, iv changed the oil pump, oil filter housing then i changed the rocker cover with the breather filter in it and it is a lot better but still smokes a bit if given a bit of wellie, think its just burning the oil that is left in the exhaust now.