had blown the previous engine yes but the rebuild included new block, new pistons, reground crank and balanced bottom end.also a different head was used and rebuilt!i thought it may have been the turbo (even though that was new also) but i sent it back to be checked and was told it was fine?!want to try another turbo really.the intercooler is also brand new.its definitely oil smoke and there is a quite a bit of it also.the engine has only been driven max 4 miles and never above 3000rpm.