Right car was working a dream last night on the way home i noticed smoke coming from the exhaust. When i started the motor this morning the car was smoking alot. I have have done a compression test on all 4 pistons and all seems well all have good compression with no major differences between them. Pot number 1 spark plug was covered in oil. i also took the car from a drive as i would of thought if i had blown a piston ring the car wouldnt run very well but this is not the car car still boosts and is very smooth. My gut feeling is the stem sills in the head. Advice needed as i really dont want to have to change a piston ring.

 

If it's come on suddenly much more likely to be a broken ring, even with ace comp, depends which one is broken.
I had ace comp/mpg/emissions from my sapph but I knew the rings were totally shagged due to 200,000 miles!!, it burnt shit loads of oil, could use 1L in 50 mile hard use no problem in the end.
Stem seals can be done with head on car easy on these, why not do these first if unsure ?
tabetha

 

i'd be looking at stem seals if they haven't been changed within the year.
if it is piston rings, then get ready to spend some money.

 

As far as I know the stem sills have not been replaced for years. The bottom end had new rings and pistons back in 2005 and the car has done about 60000 since then.

 

could be all of the above then.
i'd change stem seals first though, i've seen some properly falling apart before.