I have just completed my first 24 hour endurance test on a MTH engine. It is now just 11 minutes over the 24 hours and the engine is still pulling a consist of 15 100 ton hoppers. This was my first diesel engine that I bought one year ago. So in addition I'm not sure how many hours are on it. While I know must people would have concerns about running a train for so many hours unattended the teat went just fine. I'm sure the power company loved it. I plan on running it another 12 hours. Has any one else ever had an engine running for extended hours. NOTE: This engine suffered an overload of smoke fluid and the sound board was wiped out. It was plagued with problems such as throwing tires and leaked fluid even after several cleaning. After a complete tear down to clean the train everything still worked except the sound board. So I wanted to see if any long term damage was done to any other thing.