DPF damaged by biodiesel

Six of the 50 2008 Ford Super-Duty trucks purchased by Portland have suffered major engine damage after being fueled with high concentration biodiesel blends ranging from B50 to B99.

Portland's older trucks have not experienced any problems to date. The problem lies in the fact the 2008 Fords use a diesel particulate filter while the older trucks do not. The filters need to be regenerated periodically. This is done by adding extra injection pulses to raise the exhaust gas temperature. The process must be carefully controlled to avoid damage to the filter. Conventional petroleum diesel has specific properties and manufacturers calibrate engines to function properly on standardized fuels. Biodiesel is not a standardized fuel.

The new F-Series Super Duty's advanced Ford diesel emissions system, like other trucks in the class, injects precise levels of fuel late inthe combustion cycle to provide heat and fuel to the diesel particulate filter (DPF) to burn off trapped particulates in the DPF during regeneration. A small amount of this fuel, under certain operating
conditions, may migrate past the piston rings and into the crankcase. For normal diesel fuel, and regular oil changes, this is not an issue as much of the fuel in the oil will evaporate between regenerations.

However, biodiesel has a much higher evaporation temperature and does not evaporate appreciably. This cumulative effect can lead to significant amounts of fuel in the crankcase oil.

Ford, like other manufacturers, does not warrant that the engine will perform correctly with use of more than 5 percent biodiesel, which is clearly stated in the warranty.

Additionally, many fleet vehicles spend large amounts of time idling. Ford classifies this usage as severe duty with a corresponding oil change interval of 5,000 miles or 200 engine hours, whichever occursfirst. Every Ford Super Duty diesel engine is equipped with an odometer and an hour meter to aid in proper maintenance.

Portland City Commisioner Randy Leonard seems to think that actions directly contravening the manufacturers operating instructions somehow constitute a defect on the part of the product. So far, it looks more like a defect on the part of whoever in the city of Portland purchased these trucks and either did not read the specifications or chose to ignore them. Unless these engines had only ever been run on B5 or less and still had a problem, the city does not appear to have any grounds for a lawsuit or even demanding that Ford honor the warranty.

Click to expand...