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 Another DT466 shut down scenario
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Active Member

20 Posts

Posted - 02/17/2019 :  05:28:23 AM  Show Profile  Visit peter2019's Homepage  Reply with Quote
Guys, here is another Dt466 engine shut down scenario: randomly when your foot leave accelerate paddle which mostly at stop light, and mostly can restart right away, changed new IPR, IDM relay and check wiring are ok, unplug ICP sensor but still happened same, notice cylinder 5 is not working well, and this bus is really hard to start when the weather is cold, cranking time more than 2 minutes, here are result number after I did relative compression test: 46, 54, 49, 43, 25, 48, open the oil cap, I can see some smoke come out , doest it mean compression leaking from crankcase which is bad piston ring ? Another symptoms is this bus will shake before it shut down, like almost run out diesel, but one weak cylinder can cause engine shut down? Thanks

Brad Barker

865 Posts

Posted - 02/17/2019 :  10:48:43 AM  Show Profile  Visit Brad Barker's Homepage  Click to see Brad Barker's MSN Messenger address  Reply with Quote
This sounds like there are possible multiple issues. In order for this engine to start it has to 1. Build oil pressure sufficient to supply oil to the HPOP. 2. Crank over at a minimum rpm, I believe 150. 3. Have a clean fuel supply to the injectors of 50 psi minimum. 4. Maintain a minimum steady ICP. 5. If cold, have intake preheat. 6. Have cylinder compression. 7. Have clean power to the ECM and IDM.
Go to Navistar on command if available and obtain two checklists, hard start/ no start and performance. Follow the diagnostic test procedures. These eliminate all working components and leave you with the problem component.

Brad A. Barker
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Active Member

20 Posts

Posted - 02/17/2019 :  5:35:24 PM  Show Profile  Visit peter2019's Homepage  Reply with Quote
Thanks for reply, Brad Barker, from my recording this bus start, all the parameters are going up but for some reason drop in the middle, then start from almost beginning again, for example , RPM from 150, 240, 295 then drop to 220, 190 then goes up, same as ICP, from 730 going down to 640, 620 then up, it likes almost start but not, then building everything from beginning again, from I said that with smoke from oil cap after start, I really think cylinder 5 lost compression plus my relative compression test as above, but I donot understand, is this can cause bus shut down when you stop at traffic light? with it shakes before shut down, likes run out fuel, maybe? but at least I still have other 5 cylinders, it really shut down just because one weak cylinder?
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Senior Member

103 Posts

Posted - 02/19/2019 :  10:18:31 AM  Show Profile  Reply with Quote
should run with one dead hole for sure , I've seen alot of cams go bad and I've seen dog bones break and the roller goes side ways and takes out the cam too both open overlapping (valves)
or injector throwing up fuel instead of injection fuel in hole #5 and thats what brings down the rpm and icp readings

OEM trained in wiring and all engine platforms for 20 years
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