There are 7 owner-reported fuel system complaints for the 2004 Hyundai Sonatain NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
FUEL SYSTEM CANNOT FUEL VEHICLE PROPERLY DUE TO POOR VENT RECOVERY EQUIPMENT.... NONE OF IT IS REPLACEABLE AS REPLACEMENT PARTS ARE NOLONGER AVAILABLE...
SPLIT FUEL TANK ON THE SIDE, 2ND FUEL TANK TO FAIL IN THE LAST 5 YEARS. HYUNDAI CLAIMS THERE IS NO PROBLEMS WITH FUEL TANKS, BUT GOOGLE THE SONATA FUEL TANKS AND THERE IS A TON OF COMPLAINTS. HYUNDAI WILL DO NOTHING ABOUT IT. NO RECALL, NO NOTHING. HOUSE AND GARAGE HAS SEVERE GAS SMELL AND A LARGE PUDDLE OF GAS ON THE FLOOR. *TR
AFTER FILLING THE GAS TANK FULL, FOUND FUEL LEAKING FROM THE TANK ONTO THE GROUND. REMOVED THE TANK FROM THE CAR AND FOUND 13 RUST HOLES ON THE TOP AND SIDE OF THE FUEL TANK. HOLES WERE FOUND BENEATH AREAS OF SEALANT THAT HAD SEPARATED FROM THE TANK SURFACE. *TR
TL* THE CONTACT OWNS A 2004 HYUNDAI SONATA. WHILE ADDING FUEL TO THE VEHICLE THE CONTACT NOTICED THERE WAS A SMALL VALVE ON THE OUTSIDE OF THE FUEL TUBE THAT FRACTURED AND POSSIBLY HAD FALLEN INTO THE FUEL TANK. THE CONTACT SMELLED A STRONG FUEL ODOR EMITTING IN THE INTERIOR OF THE VEHICLE AFTER IT WAS STARTED. THE MANUFACTURER WAS MADE AWARE OF THE FAILURE AND INFORMED THE CONTACT THAT THE VEHICLE WAS NOT COVERED UNDER THE WARRANTY; THEREFORE, HE WOULD BE RESPONSIBLE FOR THE DIAGNOSTIC COST. THE VEHICLE WAS NOT REPAIRED. THE APPROXIMATE FAILURE MILEAGE WAS 47,000.
I HAVE A 2004 HYUNDAI SONATA V6 THAT GIVES ME PROBLEMS WHEN I FILL THE GAS TANK UP. I KNOW THAT THIS MIGHT SOUND CRAZY BUT, WHEN I GO TO START THE CAR, IT WILL NOT TURN OVER. I RECENTLY HAD A MAJOR TUNE-UP DONE ON THE VEHICLE ALONG WITH CHANGING THE TIMING BELT. WHEN I FILL UP MY CAR, I HAVE TO INCLUDE AN ADDITIVE SUCH AS GAS TREATMENT, LUCAS GAS TREATMENT, FUEL CLEANER, ETC. I HAD MY MECHANIC LOOK AT THE VEHICLE FOUR TIMES AND HE HAS FOUND NOTHING WRONG WITH THE VEHICLE. I ASK FOR ASSISTANCE TO DIAGNOSE THE PROBLEM AND WOULD YOU RECOMMEND BRINGING THE CAR TO A DEALER. PLEASE HELP! THANK YOU. THE SYSTEM WOULD NOT ALLOW ME TO ENTER MY VIN NUMBER. *TR
2004 HYUNDAI SONATA HAD COMPLETE FUEL SYSTEM REPLACED.*MR THE CONSUMER COULD HEAR LOAD MOANING AND RUMBLING NOISES LIKE PRESSURE BUILDING UP IN THE GAS TANK. THE DEALER REPLACED THE FUEL PUMP TWICE BUT THE PROBLEM RECURRED. *NM
WHILE PARKED FUEL FUMES ESCAPED FROM THE VEHICLE. *AK TANK AND SEALS WHERE REPLACED PROBLEM STILL OCCURED. *TC
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 25, 2026