My 2.25 petrol has been running fine since i bought it few months ago, blows no real smoke doesn't use oil or water and always starts ok. last couple of weeks a slight rattle has developed sounded like noisy tappets, but on the motorway today if was running happily at 50mph and had just done 50miles when it made a loud noise and cut out, it eventually restarted and was blowing blue/white smoke, rattling quite a lot and misfiring. Any suggestions is this likely to be a new engine job?????