Investigations
Tailpipe seperation resulting in fire
NHTSA Preliminary Evaluation PE17008 - closed, opened 2017-11-20.
NHTSA investigation PE17008 is a Preliminary Evaluation opened on 2017-11-20 and currently closed. The subject is tracked inside the Office of Defects Investigation queue. Latest activity on this investigation was logged on 2018-08-21 - NHTSA updates that field whenever an Information Request goes out, a supplement is filed, or a status change is recorded in the public docket.
A Preliminary Evaluation like PE17008 is the entry point of the federal defect-investigation process. NHTSA engineers scan complaint databases, field reports, and manufacturer data to decide whether an Engineering Analysis is warranted, whether a voluntary recall is already sufficient, or whether the pattern does not rise to a defect finding.
Investigators summarized the matter as follows: "During the review of Motor Coach Industries (MCI) Early Warning Reporting (EWR) 2016 Q4 data, field reports were identified that described fires on 2 buses from different regions of the country. These fires were alleged..." Investigations are the early-warning layer of the federal auto-safety system, sitting upstream of formal recalls and defect orders. Whether this one closes without action or escalates into an Engineering Analysis, the full history stays in the ODI archive so researchers, litigators, and buyers can pull the paper trail at any time.
Investigation Summary
During the review of Motor Coach Industries (MCI) Early Warning Reporting (EWR) 2016 Q4 data, field reports were identified that described fires on 2 buses from different regions of the country. These fires were alleged to have occurred as a result of a loose clamp allowing the tailpipe to separate from the exhaust after treatment assembly. During exhaust after treatment regeneration high temperature gases were directed at the plastic rear bumper. Prior to the fires, there were no indications (such as soot trails) that the clamps were loose. When contacted, the fleet maintenance manager stated all maintenance schedules and DOT inspections had been performed without a failure citation of the exhaust systems. MCI addressed the issue by installing additional brackets to the pipe on all the other buses in the fleet ensuring the tailpipe stayed intact should the clamp lose torque. In correspondence with another fleet using the same style bus, the fleet safety manager described having loose clamps resulting in fires. The MCI fix for the second fleet was to install a shield at the rear bumper to deflect the high temperature exhaust gases in the event of the tailpipe separated from the exhaust after treatment system. This fix was different from the first fleet. During review of communications submitted in March 2017, the Office of Defects Investigation (ODI) identified MCI Service Bulletin No. 309 regarding a maintenance procedure of the exhaust system Torca Accuseal clamp. This bulletin instructed that a new clamp must be utilized after any service or maintenance is performed in which the existing clamp was loosened or removed. ODI requested further information on this bulletin and received warranty claims showing loose tailpipes. MCI has taken the position that fires at the clamp location were due to improper maintenance by the fleets. After analysis of data, provided by MCI to ODI in response to an information request letter, ODI found there was not an increasing number
About This Investigation Type
A Preliminary Evaluation (PE) is the first phase of NHTSA's investigation process. It is opened when the agency identifies a potential safety defect pattern, usually triggered by consumer complaints, manufacturer reports, or field monitoring. During a PE, NHTSA gathers information to determine whether a formal engineering analysis is warranted.
Data from NHTSA Office of Defects Investigation. Cross-references: NHTSA recall campaign API and NHTSA FARS where fatality records overlap. PlainCars does not rate or recommend vehicles. about how PlainCars sources NHTSA data.
Read our methodology - how this data is sourced, computed, and verified.