I have a Motorhome powered by a 300hp Cat turbo diesel. I have been having an ongoing problem with engine loosing power after driving for 5 or more hours. A change of fuel filters corrects the problem and shutting down and parking for 30 min or more clears the problem. After a shut down and rest the problem will resurface after 30 min or less and after a fuel filter replacement the problem resurfaces in 5 to 10 hours. I have had the fuel tank drained and fuel filtered then treated with a biocide but the problem persists. Examination of the fuel filter elements revels a black substance. A local truck repair center tells me its fuel contamination and that I may just have to live with it and keep changing filters every 5 hours.
Any suggestions?

Dump the fuel, flush the lines and change filters. Top off with fresh new fuel. You may have to change a filter again while the systen clears.
I cant believe you refilled your tank with the original contaminated fuel. Who's idea was that?

If you know where you got the bad fuel and are nearby, go back and report it. Most of the big companies will pay to fix the problem. It sounds even thought you had the tank drained that there was contaiminate in the lines.

That was the idea of the diesel mechanic at the truck center where the tank was drained and the fuel filtered to the tune of $700.00 +

Star, I'm really curious about this, how, and what did he filter the fuel with. I'm wondering with the high cost of fuel maybe this is a new procedure.

Progress report on this problem. 1. I have no idea what the truck repair center used to filter my fuel. I do know that they treated the tank with "Clear Diesel" but I do not believe that they used "Bio Kleen". Apparently it did not solve the problem. 2. I cannot identify where the contaminated fuel originated, because the vehicle was refueled a number of times and the problem seems to be getting progressively worse. I suspect that the contaminant may have been introduced long ago and has just been building up. When the filters are cut open they reveal a black substance, I'm told that this indicates a bacterial contamination subsequent to a water contamination.

The truck repair center who drained and filtered my fuel now tells me that I may just have to live with it! (Live with having to change my fuel filter every 300 miles?)

I recently spoke with the regional representative with the company, "Power Service" specifically about the history of this problem. He recommended that I add (2) 32 oz. bottles of their "Clear Diesel" product and 8 oz. of their "Bio Kleen" product to my full 100 gal tank. I'm to let it sit over night before operating normally. when I refuel I'm to add "diesel Kleen" to the tank and then to maintain add "Diesel Kleen" to the tank quarterly. If this works I'm thinking that I may be better off periodically adding Clear Diesel or Bio Kleen to keep the bacteria in check. He said I should expect to have to replace fuel filters once or twice until the fuel system clears. I have not tried this yet so I do not know the results. If anyone has any experence using any of these products for this problem please tell me how it worked out.