ENGINE COOLING FAN BLADE FRACTURE

THE SUBJECT VEHICLES ARE BUILT ON A VOLKSWAGEN EUROVAN CHASSIS AND ARE CLASS "C" MOTOR HOMES. ON SEPTEMBER 5, 2007, THE OFFICE OF DEFECTS INVESTIGATION (ODI) OPENED THIS INVESTIGATION AS RQ 07-002 AFTER RECEIVING FOUR CONSUMER REPORTS OF FAN BLADE FAILURE ON MODEL YEAR 2002 WINNEBAGO RIALTA AND VISTA VEHICLES. AS A RESULT OF ADDITIONAL INFORMATION RECEIVED FROM VOLKSWAGEN IN RESPONSE TO RQ 07-002, THE INVESTIGATION WAS UPGRADED TO ENGINEERING ANALYSIS (EA) 08-002. THE SCOPE OF THE EA INVESTIGATION WAS ALSO EXPANDED TO COVER MODEL YEARS 2001 THROUGH 2004 RIALTA AND VISTA, 2002 THROUGH 2004 SUNSTAR, AND 2001 THROUGH 2003 EUROVAN. ALL OF THESE VEHICLES UTILIZE THE SAME ENGINE COOLING FAN. HOWEVER, THE WINNEBAGO VEHICLES ARE LARGER AND HEAVIER THAN THE EUROVAN. AS A CONSEQUENCE, THE COOLING FAN WOULD OPERATE MORE FREQUENTLY IN THE WINNEBAGO VEHICLES COMPARED TO THE EUROVAN FOR THE SAME ON-ROAD OPERATING CONDITIONS. ANALYSIS OF THE AVAILABLE DATA CONCERNING THE PROBLEM EXPERIENCE INDICATES THAT IT PREDOMINATELY AFFECTS THE MY 2002 WINNEBAGO MODELS. WINNEBAGO ACCOUNTS FOR 79% OF ALL THE REPORTS, BUT REPRESENTS ONLY 23% OF THE TOTAL SUBJECT VEHICLE POPULATION. THE MAJORITY OF THE WINNEBAGO REPORTS ARE FOR THE MODEL YEAR 2002 (64%). THE DATA SHOW A DECLINING REPORT TREND, PARTICULARLY FOR THE 2002 WINNEBAGO. REPORTS ON THE 2002 WINNEBAGO REACHED A HIGH OF 11 REPORTS IN CALENDAR YEAR 2005, DROPPING TO THREE REPORTS IN 2006, TWO REPORTS IN 2007, AND ONE REPORT IN 2008. AN EXISTING SAFETY RELATED DEFECT TREND HAS NOT BEEN IDENTIFIED AT THIS TIME AND FURTHER USE OF AGENCY RESOURCES DOES NOT APPEAR TO BE WARRANTED. ACCORDINGLY, THIS INVESTIGATION IS CLOSED. THE CLOSING OF THIS INVESTIGATION DOES NOT CONSTITUTE A FINDING BY NHTSA THAT A SAFETY-RELATED DEFECT DOES NOT EXIST. THE AGENCY WILL TAKE FURTHER ACTION IF WARRANTED BY THE CIRCUMSTANCES.