Some weird issues
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From: Scenery hill,Pa.
Some weird issues
Ive been seeing a reoccuring issue latly. Buses running off and wasting the engine which inturn destoys the whole engine. Right now i have 3 buses in my shop that have blown engines. The one look like there is oil putty in the bottom of the pan and the bus garage has every single maitnence record for it. So it been changed. IDK why but the engines have been failing at an alarming rate all over the country as to the point to thwere there are none for them to give out so therefore i have no engines to install. With the intrduction of the new 6.4 navistar has out using twin turbos like on your guys trucks and alot of better designs and 1 2 stage egr cooler they dont have many engines and most the engines that fail are not good cores. Im doing some reasearch to see if this is a on going issue here or just maybe some fluke. What navistar is saying the cause is overfulloil being sucked threw the crankcase breather. I say its the overworked injectors from regens cuase everyone has had the pintle blown out the end of the inj. The maxx7 and the 6.4 do have differences so im wondering if its something only on the maxx7 or the 6.4 too
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From: Frederick, MD
I have not heard of anyone with oil sludge. I think most have gotten the message to stick with 5K oil changes.
So as far as severe over filling of the crankcase I don't think it is widespread. Several do make oil but the amount of dillution seems to be kept in check.
So as far as severe over filling of the crankcase I don't think it is widespread. Several do make oil but the amount of dillution seems to be kept in check.
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Joined: Nov 2000
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From: Pflugerville, tx
I don't know what u said other than over full oil. and the use case is known to be the worst.. load, slow stop & go driving, worst case regen.
but if they have been doing maint, and I would guess on the severe duty cycle, the sludge makes no sense.
overworked and mechanical failure of injectors sounds like a new problem. the duty cycle on this is so high already.
Sam
but if they have been doing maint, and I would guess on the severe duty cycle, the sludge makes no sense.
overworked and mechanical failure of injectors sounds like a new problem. the duty cycle on this is so high already.
Sam
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From: Scenery hill,Pa.
This is what im concerned about. The are changing the oil as they should. The oil is sludging up. The one that has oil in the coolant is also for some reason has low compression number on clys 2,4,7. I just cant put down a rock solid reason for the issues. I honestly dont even think the oil being overfull can cause it to run off like that. I mean it would have to be all the way up to the valve covers youd think. When they go the CAC is full of oil and i mean full. I meanmaybe the engine is pulling a vacum suckin the oilout? This is a strange issue which i need to reasearch more
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From: Scenery hill,Pa.
Navistar says thats whats running the engine off and says its from an overfull oil level. They said that the boost vacum is whats sucking it in but like i said it would have to be really really full to do that. I still think its the injs blowing the tips off from it then the reason the engines CAC fills up is it from running at 7000rpm for 5 minutes befire shutting down. This is what i think is the cause and ill be sticking behind the theroy.
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From: Frederick, MD
A runaway theory is and has happened. One reason for the 5K oil change intervals. Issue for some can be down time so they extend that interval.
What compounds the issue as well is the lack of oversight. I stress with this motor and I think all modern emissions diesels that you better be popping that hood weekly.
If I was in charge of a fleet I would require daily checks before start-up.
What compounds the issue as well is the lack of oversight. I stress with this motor and I think all modern emissions diesels that you better be popping that hood weekly.
If I was in charge of a fleet I would require daily checks before start-up.
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From: EARSTERN SHORE OF MD.
(The bus garage has every single maitnence record) not accusing but any one can leave a paper trail but doing is something else!
Only time that I have seen sludge (low rpms and under worked motors.)
Check motor Hour meters these motor might run more like 15,000 miles between oil changes
Can not always change on miles, My bucket truck gets changed every 80 hours, Sometimes this is 500 miles, My 2 cents
Only time that I have seen sludge (low rpms and under worked motors.)
Check motor Hour meters these motor might run more like 15,000 miles between oil changes
Can not always change on miles, My bucket truck gets changed every 80 hours, Sometimes this is 500 miles, My 2 cents
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