The biggest thing is to establish a baseline. Once you start getting lots of samples tested and reports back, you can start seeing a trend that might be bad. I had a water pump failure in one of my Detroit's 3 years ago. Pump just blew up and got coolant in the oil. (thank god for alarms and auto shut-offs) Changed it several times after the pump was repaired. I just sent in my annual sample and that engine FINALLY is showing test results back to normal. It takes forever to truely clean out contaminates. I could tell that the oil was getting better each time, so I was not too worried. But it was reassurring to know that the testing company sent me a fax warning as soon as they tested the oil. They definately flag problems.

My mechanic buddy just laughs at me when I get oil tested. He figures it is better to budget for a major rebuild because if the tests start coming back bad on a 25 year old engine are you going to just rebuild part?

He does have a point. But I do like to try to anticipate what lies ahead.

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Alan Hamm
'87 300SDL 277K Miles
'89 560 SL 68K Miles