DieselD Posted September 5, 2007 Share Posted September 5, 2007 Here we go with another stumper. Thats been my life it seems lately!! 07 LCF with about 31k on it. poor maintance of 3-4k miles a week and only changing oil once a month. First thing was to get good oil but did not change my issue. Everything checks out it for the most part, I swapped alot of stuff over just to rule that out for cause. ICP,IPR,MAF,MAP,EBP, etc. I had some codes for MAF and IAT but this company likes to unplug stuff when their junk doesnt run right. I am having an issue with HP oil pressure. I am only seeing about 1700-1800psi WOT, I can not get above 3k rpms either. fuel pressure is ok, base engine oil pressure is good, oil is good. IPR was swapped with known good along with ICP. no wiring issues from what I can tell. I went ahead and replaced the high pressure oil pump and made a small change in results. I am now seeing about 2200-3400psi under WOT when engine is hot so its changed. Still does not run correctly and I might only see 10psi of boost if Im lucky. very erratic oil pressure still. sometimes it might be up in the 3k range then drop back down around 2200. I pulled the oil cooler out to check the screen for debris maybe starving the pump but did get much to worry about. EOT and ECT are within about 15 degrees of each other too. This was per hotline which seems stumped as well. thoughts? Quote Link to comment Share on other sites More sharing options...
Alex Bruene Posted September 6, 2007 Share Posted September 6, 2007 Are you sure that you may not have a high pressure oil leak? I find that 4.5s are terrible for leaking dummy plugs in the oil rail, especially the passenger side in my experience. Way worse for failure than 6.0s... Quote Link to comment Share on other sites More sharing options...
DieselD Posted September 6, 2007 Author Share Posted September 6, 2007 yup I performed an air check first thing to make sure. Hell I have even pulled the covers and plus to check them. replaced both stand pipes cause I had them laying around and inspected the plugs to be 100% sure. Quote Link to comment Share on other sites More sharing options...
DieselD Posted September 12, 2007 Author Share Posted September 12, 2007 well found the turbo took a dump. I was barking up the wrong tree the entire time(thanks hotline!) anyway what confused me was the low high pressure oil. I ended up getting a stock unit to swap parts until I found the issue. many parts later I swapped turbos and fixed the truck. I took apart the old turbo and found excessive coking in the smaller(secondary) turbo and excessive endplay. It would free up when hot tho so I assume this is why it ran better warm. I looked at it early on but the engine was warm when so I assume I missed it then. Now that the turbo is off and taken apart the impeller is pretty much locked up. I suspect the coking to be from the closed crankcase recall, poor maintance and extended idle time. Maybe something to look forward too in the future. This is the first turbo I have replace on a LCF due to a performance problem. Now I know what to look for. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted September 12, 2007 Share Posted September 12, 2007 And now we do too! Thanx, I'll keep the turbo in mind. Dontcha hate it when you lose focus and screw up? I was working on an LCF this morning and completely forgot that you use IDS to diagnose ABS problems, not the IC4 COM like you would for an F650/750. /forums/images/%%GRAEMLIN_URL%%/blush.gif What's worse is this is clear as day on the MD Truck launch pad display. Doh! /forums/images/%%GRAEMLIN_URL%%/boink3.gif Quote Link to comment Share on other sites More sharing options...
DieselD Posted September 12, 2007 Author Share Posted September 12, 2007 Yeah it sucks to spend so much time and overlook something. However these things are differnt way of diag and thinking compared to a 6.0. The MD software sucks in my opinion! I think this a big reason why I missed this. seeing low oil pressure on a 6.0 wouldnt indicate a turbo problem. That and never having to diag a twin turbo on a LCF. I was chasing the low HP oil instead of the low boost numbers, which really were not that low. Normally low HP oil would cause low boost so thats where I would go first. That bit me in the ass. /forums/images/%%GRAEMLIN_URL%%/crybaby2.gif Quote Link to comment Share on other sites More sharing options...
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