Keith Browning Posted October 5, 2011 Share Posted October 5, 2011 Elevated engine oil level due to fuel leaks. I haven't had too many to deal with over the years and all have been relatively easy to dignose... until today. The high pressure fuel pump leak test works well and when that passes I add UV dye to the secondary fuel filter housing. I caught a few injectors that way. I now have one where the pump leak test passed and well, I see no dye anywhere. I even inspected the pump with a black light. No bright indications of dye anywhere however I can see it (the dye) starting to mix with the oil. Perplexing. The gents at the hotline suggest replacing the pump as they claim it can leak under certain conditions like full temp operation or high pressure operation. Just curious if any of you have had any hard to diagnose concerns like this one. Quote Link to comment Share on other sites More sharing options...
JSHTech Posted October 5, 2011 Share Posted October 5, 2011 No bright indications of dye anywhere however I can see it (the dye) starting to mix with the fuel. Do you mean mix with the oil? How long does it take for the oil level to become elevated, and what kind of condtion is the DPF in? Once upon a time a hotline engineer told me that it was to be considered "normal" for the oil level to increase 1-2 quarts between oil changes due to the nature of regeneration. I assume we've all come to see and agree with this. Maybe this truck is frequently going into regeneration, and causing the oil level to increase faster than a "normal" truck. Quote Link to comment Share on other sites More sharing options...
Brad Clayton Posted October 5, 2011 Share Posted October 5, 2011 Quote: In now have one where the pump leak test passed and well, I see no dye anywhere. How many times did you run the test? I run it a minimum of 5 times in a row. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted October 5, 2011 Author Share Posted October 5, 2011 Do you mean mix with the oil? How long does it take for the oil level to become elevated, and what kind of condition is the DPF in? Yes, I meant oil. The engine is about 500 miles short of it's 5000 mile oil change interval. I drained out 24-25 quarts from the crankcase. Originally Posted By: Brad Clayton Quote: I now have one where the pump leak test passed and well, I see no dye anywhere. How many times did you run the test? I run it a minimum of 5 times in a row. Brad, I don't cycle the key any more when running the HPOP leak test. I got suckered once by a light leaker. I now run the pump with IDS at least 1/2 hour while I do other things. On this truck, I "forgot about it" for an hour. No drippies. I only ran the engine for about 10, 15 minutes the most after putting dye in it. Most of that time was idling. Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted October 5, 2011 Share Posted October 5, 2011 could engine hours be a factor? Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted October 5, 2011 Author Share Posted October 5, 2011 I am sure they could be Jim but not likely in this case. The hours are not high and the amount of fuel we are talking about is a lot more than excessive idling would typically present, especially through the summer months. Power balance and relative compression also do not show anything suspect. I have been suckered by that in the past as well but this truck runs well and doesn't smoke either. For now, I am replacing the pump and sending it on it's merry way. The customer services the truck with us regularly and I will be able to monitor the oil level in the future. Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted October 7, 2011 Share Posted October 7, 2011 FWIW... over the years, I have seen seals that will leak only when the shaft isn't turning.... I have seals that will leak only when the shaft IS turning... I have seen seals that can't seem to follow any runout or odd contours in the shaft only at certain speeds (this is an assumption or theory (you choose the appropriate term) based on non-scientific testing that depends on a concept of "resonant frequency"). Once all our testing has been done, it can often boil down to replacing "the most likely suspect"... I believe the boffins call it a "SWAG". Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted October 7, 2011 Author Share Posted October 7, 2011 Yep, and that is why the Hot-Line and I agree that the pump had to be replaced. I figured that if something in the system was likely to leak only during some specific conditions it would likely be that. But with my luck the truck will return in a 1000 miles with the same DTC and overfull crankcase condition 'cause that is how things have been going lately. I know, things aren't so bad as they can get worse. Quote Link to comment Share on other sites More sharing options...
hitechmech Posted October 7, 2011 Share Posted October 7, 2011 Higher level of ash and soot in the doc and dpf can cause oil level to increase. Seen lots of these on school buses that putt around town all day. Quote Link to comment Share on other sites More sharing options...
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