NHTSA Complaint #10100748 — 1994 PONTIAC FIREBIRD

GAS CAP FAILURE IN NORMAL USE ON 1994 PONTIAC FIREBIRD FORMULA (V8 ENGINE ). (1) THREADED PORTION OF GAS CAP, PART THAT THREADS INTO THE FILLER TUBE, BECAME SWOLLEN THRU NORMAL USE (EXPOSURE TO NORMAL GASOLINE VAPORS), TO THE POINT WHERE THE CAP WOUOLD NO LONGER THREAD PROPERLY AND SEAL. (2) SINCE THE CAP COULD NOT BE PROPERLY THREADED INTO THE FILLER TUBE, THE GAS TANK LOST PROPER PRESURIZATION/VACUUM AND THIS AFFECTED GASOLINE VAPOR RECOVERY FROM THE TANK AND ULTIMATELY, WHILE THE ENGINE WAS RUNNING, FROM THE VAPOR CANISTER. GASOLINE VAPORS WERE PRESENT IN MY GARAGE. SINCE THE SEAL WAS NOT CONTACTING THE FILLER TUBE, THERE MIGHT HAVE BEEN SOME POSSIBILITY OF GASOLINE SPILLAGE IN THE EVENT OF A ROLLOVER. (3) REPLACED THE CAP, DRIVEABILITY AND GAS MILEAGE INCREASED. CAN NO LONGER SMELL GASOLINE IN MY GARAGE. THIS COULD BE A PROBLEM IN THAT THE GAS CAP, MADE OF SOME SORT OF PLASTIC IS AFFECTED BY NORMAL GAOLINE VAPORS (THIS WOULD INCLUDE THE METHANOL ADDITIVE THAT IS FOUND AT MOST GAS STATIONS NOW-A-DAYS). THE PLASTIC SWELLS TO THE POINT THAT THE CAP IS DIFFICULT TO THREAD INTO THE FIILLER TUBE, CONSEQUENTLY, WHEN HEARING THE "THREE CLICKS", IT IS A FALSE TIGHTENING AND THE SEAL DOES NOT MAKE CONTACT WITH THE FILLER TUBE. SINCE THE SEAL DOES NOT MAKE CONTACT, DIRT AND OTHER CONTAMINATES WORK THEIR WAY UNDER THE SEAL AND FURTHER DETERIORATE IT.*AK