Navistar’s International CE school-bus unit last summer issued a voluntary recall of 15,500 school buses regarding a potential fire hazard and it became known today that one week ago, the National Highway Transportation Safety Administration’s (NHTSA)Office of Defects Investigation (ODI) launched a Preliminary Evaluation [NHTSA Action Number  PE12011]of Model Year 2008 International CE school buses.

ODI stated it has received two Vehicle Owner Questionnaires (VOQ) “alleging high pressure oil line (from the oil pump to the fuel injectors) failure on three buses. This failed high pressure oil line causes a pressure drop to the fuel injectors preventing fuel injectors from opening properly. This failure ultimately causes the engine to stall without warning. A secondary concern is the potential of a fire resulting from oil spray within the engine compartment and the hazard to other vehicles from oil spilled on the road surface.”

However, in the same statement, ODI allowed that it is “aware that the manufacturer has made an improved oil line available that is more robust than the original design.” ODI added that its Preliminary Evaluation was “opened to assess the scope, frequency, and safety related consequences of the alleged defect.”

Aspects of the ODI investigation can be accessed at www-odi.nhtsa.dot.gov/complaints , under the following identification (ODI) numbers: 10450319 and 10455151.

Issued last August, Navistar’s voluntary recall involved International CE school buses of Model Years 2007-2013. According to a Chicago Tribune news story posted online today, Navistar at the time was concerned about “apositive alternator cable that may rub on the engine mounting bracket, chaffing its insulation and causing an electrical short and a possible fire.”

The Washington Post reported online today that while …“there have been no accidents or injuries reported… In one case reported to NHTSA, a bus full of students was going 55 miles per hour when it started smoking and stalled. The driver pulled the bus to the side of the road.”

For its part, the bus and truck OEM Navistar said in a statement that "Navistar, as always, will cooperate fully with NHTSA's investigation.”

Regardless where the NHTSA investigation leads and what if any consequences there will be for Navistar, just the news of the probe caused Navistar International Corp.'s stock to fall more than 5% this  morning, noted the Chicago Tribune report. However, the newspaper added that the stock regained some losses and was down 3.76% at $33.31 at 10 am. As of  2:30 pm, it stood at $34.01.