Afternoon gents
, ok after spending some time over at the garage this morning and trying various tests and suggestions I've come to the conclusion its not the tubby 
. In fact I'm now going to wait until the bbq to get more input from folk far more knowledgeable than myself . Rolled the car out without turning over or firing up , so stone cold sober . Checked the oil level and added just under half litre , this has used that much in approx 300 miles , some of which were giving it some up the hill..lol . Took the plugs out of 1 & 3 and...
Not at all sooty and a greyish colour .
Took the intake off the tubby ,
A trace of oil in the intake , nothing on / out of the tubby , compressor wheel has a slight up / down movement , nothing in / out and feels good . Started the car and took it out for 10mins and warmed up , left idling for another 10mins with no signs of any smoke , black white or blue . Whilst idling i removed the dipstick with no signs of anything escaping from the tube , admittedly i didn't rev it , mainly because at this point i was on my own .
After all this I took it out again to try and replicate the scenario of last weeks driving , once after a sustained use of boost and then backing off to an acceptable cruising speed it did emit blue tinged smoke , quite a cloud and very noticeable in the rear mirror then it went back to nothing noticeable in a couple of seconds
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