2018 NEWMAR MOUNTAIN AIRE Engine Problems

These vehicles, built on a Spartan K3 chassis and powered by a Cummins ISX-12 engine are experiencing very high failure rates in the DEF system control head. When the control head fails, it sends error codes that result in derating engine power dramatically and/or immediate engine shut-down. This creates a very dangerous situation for anyone driving a motorhome that experiences this problem. In extreme cases, it may stop the vehicle in traffic lanes. Spartan Chassis says replacement DEF control heads are in extremely short supply and they will not provide one to a repair facility unless the affected vehicle has experienced a full derating; an initial warning message of a failing control head is deemed insufficient cause for them to provide a replacement part. Their official response is that “you must drive it until it fails before we will provide a replacement unit.” This means drivers of these motorhomes will...