larryblag

Because trials are seldom used every day, the engine oil will tend to absorb condensation after a run. Tends to be worse in cold weather and during damp climatic conditions due to a higher moisture content in the atmosphere. A good run up to normal operating temp should evaporate it off. I bet if you check the oil sight glass again after a decent run it has cleared. Only worry about this if accompanied by white exhaust smoke and/or loss of coolant which would indicate gasket or water pump trouble as mentioned by others on this post.