general rules to smoke
white smoke on startup/cold mornings = normal
white smoke constantly = bhg
blue smoke constant under acceleration = piston rings worn
blue smoke on startup = valve seals generally
blue smoke at idle but not under acceleration is generally turbo seals
blue smoke on deceleration = turbo seals
grey smoke on acceleration = tune your car
grey smoke at idle while idle rpms are all over the place = fix your boost leak
(testing the turbo) make sure your car is warm.... rev it slowly and hold it at about 2000rpm
then drop the throttle back to idle... does it then piss out with smoke? if so then more than likely your turbo seals are dead
that help?
