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Looking for opinions from diesel experts!

bagman
Explorer
Explorer
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.
Land of Opportunity & Liberty 4 ALL!
7 REPLIES 7

45Ricochet
Explorer
Explorer
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.
2015 Tiffin Phaeton Cummins ISL, Allison 3000, 45K GCWR
10KW Onan, Magnum Pure Sine Wave Inverter
2015 GMC Canyon Toad

Previous camping rig
06 Ram 3500 CC LB Laramie 4x4 Dually 5.9 Cummins Smarty Jr 48RE Jacobs brake
06 Grand Junction 15500 GVWR 3200 pin

sluper
Explorer
Explorer
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
Explorer
Explorer
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.
RFCN2
Country Coach
Jeep Wrangler Unlimited

Fifty4F100
Explorer
Explorer
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?
Glenn in TN
2008 Ford F150 King Ranch
2012 Allegro Breeze BR32
2017 Mini Cooper (future toad)

Jaxom
Explorer
Explorer
"Diesel Repair Specialists" in Dearborn Heights gets my vote as one to call.
Jerry
2015 Jayco Seneca 36FK
2011 Jeep Wrangler Sport 2 door
2011 R & R 20' Aluminum Enclosed Car Hauler
2007 Montrose 16' Aluminum Flatbed ATV Trailer

racecarfan
Explorer
Explorer
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

mccsix
Explorer
Explorer
6.7 bullet proof, MF run away quick!