Thanks Charlie
The smoke was from both stacks and I worry that if this is occurring regularly, the oil passing through the turbine section will eventually cause damage or failure of the turbine wheels due to thermal shock stresses. I don't know how often it happens. I have seen only a very small reduction in the oil levels over time. Should I be concerned? From what I understand, if the smoke was only from the right stack it would be directly from the engine transmission venting.