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RonF
Top Member
867 Posts |
 Posted - 02/06/2020 : 03:27:20 AM
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| I'm getting low oil pressure codes and warning lights on a few of my Maxx 7's. No oil pressure is created by the main bearings mostly correct? Or do I have oil pumps wearing out? |
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Gearbox
Senior Member
USA
53 Posts |
Posted - 02/06/2020 : 06:51:57 AM
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| Any chance oil is being diluted by fuel, (Oil Sample?) or change oil and see if oil pressure changes |
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RonF
Top Member
867 Posts |
Posted - 02/06/2020 : 08:20:32 AM
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quote:
Originally posted by Gearbox
Any chance oil is being diluted by fuel, (Oil Sample?) or change oil and see if oil pressure changes
If it is, it isn't much because the oil level on the 3 in question is right between the marks. All other preliminary stuff has checked out and taken care of.
The idling pressure after everything is good and hot drops near 15 psi. Off idle goes anywhere from 30- 70 depending on RPM.
It's just the idle pressure. Not sure if changing the oil pump would help or not. Their not cheap. |
US Army retired CMBT |
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g0ttadrift
Advanced Member
USA
258 Posts |
Posted - 02/07/2020 : 5:19:03 PM
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| What year buses do you have? We have 07' Maxxforce DT and we had a similar issue on a couple of them. It ended up being a bad reading from the oil pressure sending unit. Threw codes and made the gauge read low at idle. We have front engine buses so the sender is by the right front wheel well on the frame. |
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iceracer
Active Member
32 Posts |
Posted - 02/08/2020 : 2:28:53 PM
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We have the same issue on our 2011 and newer Maxx 7's. I did some oil sampling and found fuel dilution, have gone to 6k oil changes to prolong the inevitable. We have lost 3 engines under 130k miles, these same buses started having issues well under 100k. I know of other fleets that are changing oil at 4k!
We also have 15 2010's, and with what I am seeing, I need to get rid of the newer ones first!
from my observation, and limited knowledge, I often wondered why I have black fuel filter cartridges when I change them, (like as black as my oil filter!) so I started doing some research... I didn't see that with the older emission buses. Find out that as they (IC) had to meet the next level of emission testing, they had to increase fuel rail pressures and get them to run hotter.
well, search the following and make your own assumptions…
ASHPALTENE
BIO-FUELS
ULS DIESEL FUEL
MAXXFORCE 7 LAWSUITS
We are doing what we can to keep them running, but we know its only a matter of time. |
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TRex
Senior Member
89 Posts |
Posted - 02/10/2020 : 10:19:27 AM
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| Two thoughts. If you do not have the regen inhibit feature it can be added. This will keep them from regenning on their own which IMHO is a big part of the fuel dilution problem. That only works if your drivers report that the regen needed indicators lights have come on. This lets you then put it in a parked regen and let the regen run until it is done. Many times they try to do an active regen while in use. On highway that strategy works. Sort of. In stop and go the soot level doesn't get pushed down very far before the process is interrupted. So it keeps doing it and of course it is putting fuel in the cylinders every time. 2nd the Nexiq Blue Link code reader that pairs to a tablet shows the amount of time in regen and the amount of fuel used. I do not see that info anywhere else. Not even in NEDS's. Not sure but I think the asphatene problem is tied to fuel quality. It is not a universal issue. |
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woodster67
New Member
5 Posts |
Posted - 03/03/2020 : 11:49:55 AM
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| I have a 2013 currently at dealer had DPF changed last year.Well it went bad causing bad pressures which caused constant regens which kept diluting oil with fuel. also your dpf pressure sensor can go bad or low voltage causing excessive regens.I have another 2013 maxxforce going on its 3rd enginge and only has 59,000 miles |
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Maxx Force & oil pressure
