RoadVitals

2018 Newmar Mountain Aire Problems

Owner-reported complaints filed with NHTSA, grouped by component

Data refreshed

Owner complaintsComplaints are reports submitted to NHTSA by owners and drivers. NHTSA does not verify most reports before publishing them, and a complaint does not establish that a defect exists. Volume is influenced by how many of a vehicle were sold, how long it has been on the road, and how much attention an issue has received.
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Latest Jul 7, 2021
Components namedHow many of our component categories appear on at least one report for this model year. One report can name several.
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Crash or fire reportedComplaints whose submitter recorded that a crash or a fire occurred. These are the reporter's own answers on the NHTSA form, not verified findings.
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What this page shows

Everything below is an owner-reported complaint submitted to NHTSA about the 2018 Newmar Mountain Aire, grouped by the component NHTSA recorded on the report. These are not confirmed defects, and they are not recalls. NHTSA does not verify most reports before publishing them, and a category with more reports in it is not evidence that a part is defective.

Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.

Reports by component

Ranked by how many owner reports name each component category

  • Engine1100.0%

Percentages are of component mentions. A single complaint can name more than one component, so these do not sum to the total complaint count.

Each component in detail

What the reports in each category say, in the owners' own words

Engine

Reports naming the engine itself — including stalling, misfires, oil consumption, cooling and internal engine components.

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report

From owner reports, verbatim

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 either be subject to sudden (and, potentially very dangerous) engine shut-down, or they must cease using their expensive motorhome until such time as Spartan Chassis feels they again have a sufficient stock of replacement units. Many motorhome owners use their vehicles full time; they are their home. The inability to safely use them places a huge burden on those owners. I believe NHTSA needs to issue a recall on affected vehicles and direct Spartan Chassis to implement a software emergency bypass of the engine derating caused by a faulty DEF control head. It is my understanding that this software bypass solution already exists and is currently implemented on emergency vehicles (fire trucks) produced by Spartan Chassis.

NHTSA ID 11423856 · filed Jul 7, 2021

Too few reports in this category for a page of its own — they appear in the full complaint list.

Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.

Elsewhere on this vehicle

Data sources

Data on this page last refreshed .