Well, here we are in Ypsilanti Michigan at Wolverline Frieghtliner. Our saga started Sunday July 3rd when halfway through the Pennsylavania Turnpike the Cat C7 started "pinging" mysteriously after filling with diesel at a turnpike rest stop. Drove another fifty miles to a rest stop and called Freightliner Hot Line and was told a number to call. This being Sunday night the closest road service had to come from two and a half hours away. Bob arrived at around eleven p.m. and claimed fuel may have been contaminated, so not having the proper replacement filters, he emptied out the secondary engine mounted filter with diesel conditioner. We added motor oil, settle up [$466] and we bunked for the night. Sunday we start our trek to Michigan and the noise was still there, called the road service shop and were told bad fuel has to "work its way out". On we went and the noise continued to get worse. We're now waiting for a determination from the folks here. Will keep you posted.