EGR's Effect on Oil Degradation and Intake System Performance

Oil Quality in Diesel Engines With On Line Oil Cleaning Using a Heated Lubricating Oil Recycler

“…The reduction was greatest for the Austin taxi (78% at 100 hours) and least for the Ford engine (40% reduction at 100 hours) and intermediate for the Cummins C6 at 60% at 350 hours. A warning level limit of Chromium in oil is 10ppm (34,39) and a condemned limit is 30 ppm (34). In none of the tests was the 10ppm limit reached, although after 17000 miles with the recycler the Cummins C6 engine was just approaching 10ppm in the oil.…”

“…None of the iron contents in Fig. 28 are of concern as 100 ppm iron is the usual level at which a warning is issued in oil condition monitoring and 200 ppm is a typical oil condemnation limit (34,39).…”

Fouling Problems in Exhaust Gas Recirculation Coolers in the Automotive Industry

“…Zhan et al [14] concluded from their experiment that fouling was virtually undetected in the EGR cooler under these conditions, and that both the pressure drop across the EGR cooler and the cooler effectiveness remained constant throughout the 45 h of the test. However, DOC and DPF are quite expensive and installing them into a diesel engine can introduce a substantial pressure drop that can influence the efficiency of the engine [10][11][12]. Using a DOC with a DPF before an EGR cooler to prevent fouling has not been realized in practice, and is still a point of further research.…”

“…As a result, the recirculated exhaust can be free of particulates and unburned hydrocarbons (HC), and thus the cooler can be kept much cleaner. However, it appears that the majority of manufacturers plan to use high-pressure loop EGR because it may offer somewhat better fuel efficiency [10][11][12].…”