If there is any "secret" to what I'm doing, it's that well designed diesel engines need only clean fuel and to be run in their optimal temperature range regularly and they will deliver LONG trouble free service so long as the oil/filters of suitable quality are changed at prudent intervals. When they are abused (run for short intervals and at low engine speeds) even extraordinary maintenance will not offset the destructive consequences and the engines WILL deteriorate and at some point they will fail not from poor design, but from poor application. There are many thousands of diesel engines available that have balked at the abuse their owners have subjected them to that could be revived, but maintenance alone WILL not do the job. They MUST also be driven as they were designed to be driven or they will prematurely fail, the victim of inappropriate use. There are also some engines out there that have gone over the edge and will NOT be successfully revived. Fortunately for us, the bulk of the mechanics and shops working on these machines (conditioned by the gasoline car maintenance that comprise the vast majority of their experience) will condemn almost all of these cars, allowing US to buy them at bargain prices and restore the majority of them to proper function. Marshall Booth, Ph.D. I have been a professional mechanic for over 30 years and have driven many different brands of cars. I find old MB diesels to be the most reliable and durable cars ever, not requiring anything more than routine maintainence, once I get other people abuses to them sorted out. John Berryman