NHTSA Office of Defects Investigation
Preliminary Evaluation PE17-008: Tailpipe seperation resulting in fire
- Closed
NHTSA's Office of Defects Investigation opened Preliminary Evaluation PE17-008 on November 20, 2017 and closed it on August 21, 2018. NHTSA's investigations file lists the 2011–2017 MCI D4505 for it.
Updated daily from NHTSA's investigations file
Key facts
- NHTSA number
- PE17-008 (also written PE17008)
- Investigation type
- Preliminary Evaluation The first stage of most defect investigations: NHTSA's Office of Defects Investigation gathers basic information about a possible safety defect, including from the manufacturer.
- Status
- Closed August 21, 2018
- Opened
- Closed
- Vehicle or equipment manufacturer
- Motor Coach Industries
- Component
- Engine and Engine Cooling — Exhaust System
- Vehicles and equipment
- 2011–2017 MCI D4505
A recall appears here only when NHTSA's investigations file links one to the investigation; NHTSA's summary or record can name others.
NHTSA's summary
As NHTSA's Office of Defects Investigation wrote it for Preliminary Evaluation PE17-008.
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 (claim rate of 1.1%) of failures and fires even with portions of the fleet having over seven years in service.
The 4 fires identified were from 2 fleets.
ODI contacted the fleets with fire incidents and was informed that one of the two buses involved in the fire incidents was sold in 2016 and other fleet does not have maintenance records since they only keep records for one year.
ODI is closing the investigation as no actionable trend has been identified.
This investigation is closed. Further use of agency resources does not appear to be warranted. The closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exist. The agency reserves the right to take further action if warranted by the circumstances.
Vehicles and equipment listed for this investigation
NHTSA's investigations file lists these vehicles and equipment for Preliminary Evaluation PE17-008. A listed model year means only that an investigation names it; it says nothing about any particular vehicle. Model years with a try.vin recall page link to that page's NHTSA investigations section.
What an NHTSA investigation is
NHTSA's Office of Defects Investigation (ODI) looks into possible safety defects in vehicles and equipment, often after owner complaints. An investigation usually starts as a Preliminary Evaluation, or as a Recall Query when it concerns whether an existing recall covers the right vehicles or fixes the problem, and ODI can upgrade it to a more detailed Engineering Analysis. A Defect Petition asks NHTSA to open an investigation, and Audit and Equipment Queries are administrative investigations into whether companies complied with federal vehicle safety requirements, such as reporting, recall and certification rules.
An open investigation is not a finding that a safety defect exists, and NHTSA can close one without a recall.
To see whether a specific vehicle has an open recall, enter its VIN at nhtsa.gov/recalls.
Free VIN check: decode a VIN to see its year, make and model.
Sources
NHTSA's investigation record for PE17-008
Investigation details come from NHTSA's investigations file, which try.vin imports once a day. The investigation types are described from the U.S. Department of Transportation Inspector General's May 2023 report on NHTSA's Office of Defects Investigation, NHTSA's petition rules (49 CFR Parts 552 and 557) and NHTSA's Office of Defects Investigation procedures. How try.vin reads NHTSA investigations.