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bagman's avatar
bagman
Explorer
Jul 14, 2015

Looking for opinions from diesel experts!

I've been advised by a good friend that if I was to buy a motor home and had a choice between the International/Navistar MaxxForce 7 or the Cummins 6.7 that it would be wise for me to avoid the Navistar engine as they are problematic. Yesterday we returned a 26,000 Penske Dura-Star straight truck back to Penske and I asked if they were having any issues with their MaxxForce 7 engines. They said no and every straight truck in the lot was a Navistar, except for (1) Hino. So I'm asking you guys what do you think, plus I'm going to call 2-3 Diesel Repair businesses in the Detroit area and get their opinion. However, what I'm afraid of is most of the dudes here probably only have past experience with CAT & Cummins. Pleas feel free to express your opinion. The Navistar engine does NOT use DEF. Bags. PS: I've owned (6) diesel trucks, but don't consider myself an expert.
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  • 45Ricochet's avatar
    45Ricochet
    Explorer
    Apr 26, 2016
    sluper wrote:
    The Navistar in either the 6.0 or 6.4 version were terrible engines for anyone that had a problem with them, kind of like the old GM before Isuzu. Lots of places to find out about the problems of the engines if you look, remember all people have opinions. Issues with the DEF is it is temperature sensitive and deteriorates in temps above 85 degrees.
    Cummins attempt without DEF cost them mileage per gallon which has increased with the use of DEF in the newer engines.

    X2
    Navistar just leaves a sour taste in my mouth. Yes most likely Ford engineers were to blame for the 6 doh and 6.4 issues but none the less Navistar was the engine builder.
    And a non DEF engine trying to keep up with the EPA will be a problem child. Don't matter the brand, it will clog up in time.
  • sluper's avatar
    sluper
    Explorer
    Apr 25, 2016
    The Navistar in either the 6.0 or 6.4 version were terrible engines for anyone that had a problem with them, kind of like the old GM before Isuzu. Lots of places to find out about the problems of the engines if you look, remember all people have opinions. Issues with the DEF is it is temperature sensitive and deteriorates in temps above 85 degrees.
    Cummins attempt without DEF cost them mileage per gallon which has increased with the use of DEF in the newer engines.
  • RFCN2's avatar
    RFCN2
    Explorer
    Apr 25, 2016
    If I was to buy another coach I would call a couple of places that repair the motors in question and ask them for their opinions. We have a CAT motor that has been very good. But CAT makes some motors not as good. Same thing for Cummins and MaxxForce.

    Navistar lost a huge huge amount of money trying to get the Maxxforce motor to work without DEF. There have been significant issues with some of their motors. We talked to some people who had one and listened to their tale of woe.
  • Fifty4F100's avatar
    Fifty4F100
    Explorer
    Apr 25, 2016
    bagman wrote:
    I've been advised by a good friend that if I was to buy a motor home and had a choice between the International/Navistar MaxxForce 7 or the Cummins 6.7 that it would be wise for me to avoid the Navistar engine as they are problematic. Yesterday we returned a 26,000 Penske Dura-Star straight truck back to Penske and I asked if they were having any issues with their MaxxForce 7 engines. They said no and every straight truck in the lot was a Navistar, except for (1) Hino. So I'm asking you guys what do you think, plus I'm going to call 2-3 Diesel Repair businesses in the Detroit area and get their opinion. However, what I'm afraid of is most of the dudes here probably only have past experience with CAT & Cummins. Pleas feel free to express your opinion. The Navistar engine does NOT use DEF. Bags. PS: I've owned (6) diesel trucks, but don't consider myself an expert.
    Seems this thread just died. I'm looking at a 2012 Allegro Breeze with the Maxxforce 7 engine. Its brother is supposed to be the 6.4 Powerstroke in the Ford Superduty. This was a decent engine. Much better than the 6.0 debacle but maybe not as good as the bullet proof 7.3. Do I keep looking and maybe buy or run away?
  • Jaxom's avatar
    Jaxom
    Explorer
    Jul 14, 2015
    "Diesel Repair Specialists" in Dearborn Heights gets my vote as one to call.
  • racecarfan's avatar
    racecarfan
    Explorer
    Jul 14, 2015
    mccsix wrote:
    6.7 bullet proof, MF run away quick!

    the nav your referring to I believe to be a very good motor the one bigger I believe there were some problems.I have two close friends with Nav engines in a 2012 Monaco and a 2013 and they both have zero problems with the nav engine. there are hundreds of thousands of NAV engines out there

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