Bear in mind I'm new to diesels so I don't know if this is in my head...I don't think my car did this when I first got it, think I first noticed it opening the throttle around 1700rpm and thinking 3rd will be ok. Kind of speed where I could have dropped down to 2nd. Anyway, this is the zone where turbo spools up right? My car gets a bit growly, there a definite grunty tone. There's no smoke, runs and pulls fine, no tappet noises and no whistling and after 2000rpm it's what I would consider as normal for a diesel with an open throttle. Is this growly tone through this part of the rev range (1700-1900) normal? Forgive me if it's a daft question, I'm just wondering if it's something worth worrying about, not sure it seems quite right. In a higher gear at lower speeds its worse but then I would expect it to be due to torque loading. Car is otherwise very smooth and quiet (for a diesel).

My bet is on the EGR.  Does it get a bit of 'stutter'?  BLT engine so 99% likely would be that. I had plenty of headache with same thing plus mine puffed a cloud of smoke.  EGR disabled and problem gone.

( a garage replaced wiring loom and inj. seals for £350 and and gave me the car with same issue Grrrrr, I was not impressed)

 

Try to unplug the vacuum hose from your EGR valve  ( put temporarily a screw into the vac hose 'golf tee mod') and take it for a drive...see if it gets better. 

Cheers for the suggestion. I'm in the process (when I get chance) of turning down the adaptation for it, I also have the gasket with the reduced hole which I intend to drill out to 12mm. Do the cheap things with it first, I will delete it down the line but car is on finance so have to be careful with mods. I do get a slight stutter, usually higher gears bang on 1800rpm when I reapply a light throttle. The stutter is not worryingly bad but sure it could be improved with these tweaks.

Yep, bang on at 1800rpm. I tried the new gasket and drilled it to 12mm...it made an improvement, but not good enough to live with it.   Now it's all mapped out and the problem has gone.

Ok sit rep, the car was in the garage next door for an investigation of slight oil seepage from the rocker cover gasket. It was in there because if the cover was warped I may have been able to warranty it, anyway it turns out gasket is ok, cover is ok but a couple of bolts are dodgy. One where seal had gone and another (more worryingly) at the front where thread is gone in the head. Anyway not leaking from there and he's going to get a helicoil or something for it.

So while he was there I asked him to drill out the gasket and put it in, and in taking off the egr he brushed out the worst of the cack in it. Upshot is, like you say stuttering has improved but not totally gone, car seems to run generally better and pulls a bit stronger higher up. The growly noise has been reduced to a brief blip in 2nd across 2000rpm, it's still notable in 3rd but is slightly better I would say. Could be that my intake mani also needs a clean out. I will also try turning down the adaptation. At least now I have some peace of mind with the rocker cover gasket and some improved running. Deleting the thing will undoubtedly help more but as I say I need to be a bit careful with mods for the time being.