Recent developments in diesel engines and fuel injection equipment together with the move to ULSD and bio-blends have seen an increase in reports regarding deposits in both injectors and filters.
Historically deposits have been generated from a number of sources: bio-contamination, both aerobic and non-aerobic, water contamination, lube oil adulteration, additives, dirt, metals in fuel, and biodiesel degradation. These may be ascribed to “poor housekeeping,” incorrect additivation, deliberate adulteration or some combination.
However the recently observed deposits differ from these. The deposits are described and indicate possible precursor molecules that support proposed mechanisms and their ability to form filter deposits.