NHTSA Investigation PE87042

EXHAUST SYSTEM HEAT

SUMMARY OF INFORMATION FROM MANUFACTURER:HIGH UNDERHOOD AND EXHAUSTTEMPERATURES ARE A CUSTOMER SATISFACTION CONCERN INVOLVING A VERY LIMITEDNUMBER OF VEHICLES OPERATED BY A FEW SEVERE SERVICE FLEET LOCATIONS.WEARE NOT AWARE OF ANY ACCIDENTS OR FIRES CAUSED BY THE CONDITION, AND WE DONOT CONSIDER IT TO PRESENT A RISK TO MOTOR VEHICLE SAFETY.ANALYSIS:EPA REQUIREMENTS FOR HEAVY DUTY VEHICLES CAUSED EMISSION SYSTEMCHANGES FOR THE 1985 AND 1987 CALENDAR YEARS.BEGINNING IN 1985 DUAL AIRPUMPS REPLACED THE SINGLE UNIT, AND DUAL CATALYTIC CONVERTERS WERE ADDED IN1987.THE CHANGES INCREASED UNDERHOOD AND EXHAUST SYSTEM TEMPERATURES.CONCERNS INCLUDE DRIVEABILITY AND VAPOR LOCK PROBLEMS DUE TO HOT FUELHANDLING AND HEAT DAMAGE TO THE 4 WD DISCONNECT VACUUM RESERVOIR, EXHAUSTSYSTEM HANGERS, SPEEDOMETER CABLE, AND WINDSHIELD WASHER BOTTLE.CURRENTLYMEANS TO REDUCE AND BETTER MANAGE THE TEMPERATURES ARE BEING STUDIED.CONSIDERATIONS ARE: AIR PUMP DIVERTER SYSTEMS, HEAT SHIELD FOR AFFECTEDUNDER BODY COMPONENTS, AND REROUTING FUEL SUPPLY LINES AWAY FROM HEATSOURCES.ADDITIONALLY FIVE TECHNICAL SERVICE BULLETINS HAVE BEEN ISSUEDREGARDING VAPOR LOCK ON THE SUBJECT VEHICLES.PROPOSED ACTION:CLOSE THIS PE.NO SAFETY RELATED DEFECT HAS BEENDETECTED.===

An investigation is a separate record from a recall and from a manufacturer communication. A manufacturer campaign to repair a safety defect or a failure to meet a federal safety standard.