Ok so i bought my y reg TD4 in June probably paid to much for it. First thing i did was give it a service, used castrol magnatec 5/30 and brit part filters. At the same time changed the pcv to the bmw cyclone type and cleaned out egr and air box. Stupidly i overfilled with oil, tried to put the full 6.5 litres in without checking dipstick. This produced heaps of blue smoke. My problem now is after draining oil to minimum it still produces blue/grey smoke between 2000 and 3000 rpm. After hours of investigation i realized that a previous owner or mechanic had put the turbo vent filter on the IRD breather pipe and left the turbo vent open without a filter. I removed the vacuum pipe which was clogged but not fully blocked i tried to test the solenoid to see if it still worked (didn't do this the sensible way by looking at the turbo actuator rod for movement). Bought myself a new solenoid £51+VAT and fitted this morning still the same problem. Looked at the rod to see if it moves and it does but only when you blip the throttle and returns immediately to its original position, If you build up the revs it doesn't move at all. Can someone tell me if this is normal (cant believe it is) and if they know what might be causing it. I think the problem is boost pressure related as it only reads between 0.0 and 0.4 bar through the rev range and doesnt read any until after 3000 rpm. I have already replaced the MAP sensor in the intake manifold.