My 87 gn smokes sometimes when I first start it up after the car is warm. The car does not smoke when starting in the morning or when the car cool down. It doesn't smoke on every start. The motor is a fresh rebuild, although I used the same turbo that came on the car when I purchased it 2 years ago. I have no idea how old it is. The shaft play seemed to be very little. Is this a sign of the turbo going bad? It does not smoke when idling or at cruise speed. Any ideas guys.