There are 35 owner-reported engine complaints for the 2004 Toyota 4Runnerin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
HAD A MISFIRE IN #6 CYLINDER AT 155K MILES. I TOOK IT TO A DEALER AND THEY TOLD ME THAT I HAD A HEAD GASKET STARTING TO GO BAD THAT LET COOLANT INTO THAT CYLINDER AFTER I SHUT THE ENGINE OFF RESULTING IN A ROUGH COLD START. THE TECH SPECIALIST GAVE ME SOME NICE INFORMATION AND AFTER RESEARCH I LEARNED TOYOTA KNEW ABOUT THE FAULTY HEAD GASKETS IN THEIR VEHICLES AND CAME OUT WITH A NEW REDESIGNED ONE, BUT THEY NEVER TOLD CONSUMERS AND REFUSE TO FO ANYTHING ABOUT IT. NOW MY CAR IS IN THE SHOP AND QUOTED AT $3200.
BLOWN HEAD GASKET AT 150K MILES. POTENTIAL TO OVERHEAT TO OVERHEAT WHILE IN OPERATION LEAVING THE PASSENGERS STRANDED OR START AN ENGINE FIRE. EVERY LOCAL MECHANIC SHOP I RECEIVED ESTIMATES FROM IN KNOXVILLE WAS VERY FAMILIAR WITH THIS ISSUE FOR THIS MODEL YEAR AND THE INTERNET FORUM SEARCHES HAVE HUNDREDS OF COMPLAINTS FOR THIS SAME ISSUE. NO RECALL HAS BEEN ISSUED FOR THIS PROBLEM.
BLOWN HEAD GASKET WITH 130,000 MILES. BLOWN NEAR THE NUMBER 6 CYLINDER (LIKE EVERYONE ELSE). COST $3700 FOR REPAIRS.
EVENT OCCURRED AT START UP. WARNING LIGHTS >>> CHECK ENGINE, VSC TRAC, AND TRAC OFF. PER TOYOTA DEALERSHIP >>> FOUND HEAD GASKET ALLOWING ANTIFREEZE TO LEAK INTO CYLINDER 6 CAUSING P0306 REPLACED BOTH HEAD GASKETS COST $2644.91
VEHICLE ENGINE LIGHT AND OTHER LIGHTS CAME ON, TOOK TO DEALER AND TOLD ME CODE WAS PO306 CODE WAS DIAGNOSED STATING THERE IS A MISFIRE IN CYLINDER #6 RESULTING IN A HEAD GASKET PROBLEM OF COOLANT ENTERING THE CYLINDER & IT WOULD COST ME 3000 TO 5000 DOLLARS TO FIX. EVERY TIME I START CAR IN MORNING THE CAR HAS A ROUGH SHACKING START UNTIL WARMED UP, MY CAR HAS 135000 MILES & REVIEWING ONLINE THIS IS A COMMON PROBLEM WITH THIS ENGINE AROUND OR AFTER 120000 MILES AND THAT THEIR ARE HUNDREDS OF COMPLAINTS WITH THE EXACT SAME ISSUE I AM HAVING. PLEASE CAN ONE GET HELP IN GETTING TOYOTA ACCOUNTABLE FOR A PROBLEM THEY SURELY KNOW ABOUT AS WELL AS BECAUSE I AM NOT THE FIRST AND PROBABLY NOT THE LAST ON COMPLAINING ABOUT THIS ISSUE & THAT THIS IS NOT A NORMAL PROBLEM FOR THIS ENGINE IT IS A MANUFACTURES DEFECT
THIS 2004 TOYOTA 4RUNNER HAD 145000 MILES ON IT WHEN THE CHECK ENGINE LIGHT CAME ON, ALONG WITH VSC AND VSC TRAC LIGHTS. ENGINE RAN ROUGH/RUMBLED FOR FEW SECONDS AFTER EACH START, THEN THE RUMBLING WOULD STOP. AT AUTOZONE THEY DIAGNOSED A P0306 ERROR CODE. TOOK IT TO THE DEALER WHO SCANNED CODE # 0306 #6 CYLINDER MISFIRE. FURTHER TESTING SHOWED COOLANT SEEPING UNDER HEADGASKET, AND DEALER RECOMMENDED REPLACING CYLINDER HEADGASKET. RESEARCHING THE ISSUE, IT LOOKS LIKE IT'S NOT AN UNCOMMON PROBLEM WITH THIS PARTICULAR CAR AT THIS MILEAGE. WHAT MADE ME FILE THIS COMPLAINT IS THAT EACH SINGLE ONE OF THE OWNERS WHO POSTED ONLINE MENTIONED THIS PARTICULAR DIAGNOSIS CODE OF CYLINDER #6 MIFIRE. I FOUND ITINTERESTING THAT EVERYBODY HAS THE SAME EXACT PROBLEM, AND NOT EVEN ONCE IT WAS ANY OTHER CYLINDER MISFIRE BUT # 6. I HAD THE DEALER REPLACE THE HEADGASKET, WHICH TOOK CARE OF THE PROBLEM, BUT SINCE IT'S A RECURRING PROBLEM, I THINK TOYOTA SHOULD TAKE OF THIS ISSUE.
MY 4RUNNER CHECK ENGINE LIGHT CAME ON AND THE VSC TRAK OFF LIGHTS CAME ON WITH IT. THE TROUBLE CODE INDICATED #6 CYLINDER MISFIRE. AFTER CHECKING ALL THE SENSORS IT BECAME OBVIOUS THAT THERE WAS A SLIGHT LOSS OF COOLANT. CHECKED THE ENGINE AND FOUND THAT THE HEAD GASKET FOR #6 HAD FAILED. LOOKING ON LINE I SEE THAT THERE ARE HUNDREDS OF COMPLAINTS ABOUT SIMILAR PROBLEMS AROUND THE 120K MILES MARK. ISN'T TOYOTA REQUIRED TO REPORT THESE TO NHTSA AND SHOULD THERE BE A RECALL ON THIS? THIS PROBLEM SEEMS VERY SIMILAR TO AN EARLIER TOYOTA ISSUE THAT RESULTED IN A RECALL. A HEAD GASKET SHOULD NOT FAIL DURING NORMAL USE OF A VEHICLE ESPECIALLY ONE THAT IS USED VERY LIGHTLY AND NOT OFF ROAD.
CYLINDER 6 MISFIRES CAUSED BY OIL LEAKING INTO CYLINDER 6 COMBUSTION CHAMBER AROUND SPARK PLUG. THE ISSUE IS TRACED BACK TO A HEAD GASKET FAILURE ON THE 2004 4RUNNER V6 ENGINE. CYLINDER 6 IS THE WEAK POINT WHERE SUCH FAILURES OCCUR ESPECIALLY AT START UP AND WHEN THE ENGINE IS COLD. THERE IS CLEARLY A DESIGN FLAW IN THE 2004 V6 4RUNNER'S HEAD GASKET WHICH REQUIRES MANY HOURS OF LABOR TO REPAIR AND SHOULD BE COVERED BY TOYOTA. *TR
AFTER READING ONLINE THERE ARE HUNDREDS OF REPORTS OF CYLINDER #6 FAILING WITH A HEAD GASKET ISSUE WHICH RESULTS IN A 2500-4000 $$ REPAIR BILL. TOYOTA HAD A MAJOR RECALL FOR THE 2ND GENERATION 4RUNNER BECAUSE OF HEAD GASKET ISSUES. THEY REALLY NEED TO ADDRESS THIS ISSUE B/C THERE IS OBVIOUSLY A MAJOR PROBLEM WITH THE 2004 4RUNNER V6 ENGINE. *TR
ENGINE IS LEAKING COOLANT INTO THE #6 CYLINDER CAUSING MISFIRE, ROUGH IDLE, AND CHECK ENGINE LIGHT TO ILLUMINATE - APPARENTLY A VERY COMMON PROBLEM WITH THIS V6, 4.0L ENGINE LEAKING AT THE #6 CYLINDER - OBVIOUSLY A MANUFACTURING DEFECT TO HAVE HEAD GASKETS FAILING AT THE SAME LOCATION. *TR
ROTTEN EGG SMELL FROM REAR OF TRUCK. WORSE WITH REAR WINDOW OPEN.
WHILE DRIVING, THE CEL (CHECK ENGINE LIGHT) CAME ON AND THE VSC TRAC AND VSC OFF LIGHTS CAME ON AS WELL. APPARENTLY TOYOTA DISABLES VSC WHEN THE CEL IS TRIGGERED. IN MY CASE, THE 2 TIMES IT HAS OCCURRED HAS BEEN DUE TO EMISSIONS RELATED FAILURES (1ST TIME THE CAT FAILED, 2ND TIME ONE OF THE O2 SENSORS FAILED). IN THE 1ST CASE, I IMMEDIATELY TOOK THE VEHICLE TO THE DEALERSHIP AS I WAS APPROACHING THE END OF THE EMISSIONS WARRANTY. THEY MADE THE REPAIRS AND CLEARED ALL THE CODES SO WASN'T AWARE THAT THE VSC SYSTEM WAS ACTUALLY DISABLED. THE 2ND TIME (O2 FAILURE) I REPLACED THE FAILED O2 SENSOR, THE CEL HAS CLEARED, HOWEVER THE VSC LIGHTS ARE STILL ON AND VSC IS DISABLED. I HAVE SERIOUS CONCERNS THAT TOYOTA DISABLES KEY SAFETY SYSTEMS DUE TO EMISSIONS RELATED FAILURES ESPECIALLY GIVEN THE INHERENT STABILITY PROBLEMS WITH SUV'S. IF I'M ON A TRIP WITH MY FAMILY AND AN O2 SENSOR FAILS, OR A CATALYTIC CONVERTER FAILS, OR THE GAS CAP FAILS, KEY SAFETY SYSTEMS THAT HELP KEEP MY FAMILY AND I SAFE SHOULD NOT BE DISABLED! I THINK THIS DESERVES AN INVESTIGATION. *TR
THIS INCIDENT WAS 1ST NOTICED 12/9/2009. I STARTED MY CAR IN THE MORNING AND LET IT WARM UP, WHEN I WENT TO GET IN IT A FEW MINUTES LATER, THE HEATER FAN WOULD NOT WORK. SINCE THEN, I FIND THAT THE HEATER FAN WILL WORK OFF AND ON, SEEMS TO BE AFTER VEHICLE HAS WARMED UP A BIT -MAYBE (NOT SURE OF THE RHYTHM OR REASON). I DO NOT FEEL SAFE DRIVING THIS VEHICLE IN COLD WEATHER ESPECIALLY SINCE I HAVE SMALL CHILDREN AND FEAR GETTING STUCK OR STRANDED WITH NO HEAT! I PURCHASED THIS VEHICLE IN DECEMBER OF 2008 AND DROVE IT ALL LAST WINTER WITH NO PROBLEMS-THEREFORE I AM CONCERNED AS TO WHEN AND WHERE IT WILL MALFUNCTION AGAIN. *TR
1.) THERE IS A SERIOUS "CLUNK" NOISE WHEN BRAKING AND ALSO THE SAME NOISE WHEN STARTING FROM A COMPLETE STOP WHEN YOU TAKE FOOT OFF BRAKE. 2.) THERE IS "SULFUR SMELL " IN CABIN FROM CATALYTIC CONVERTER. *TR
EXCESSIVE SULFUR SMELL WHEN ACCELERATING. OCCUPANTS OF THE CAR CAN SMELL THE SULFUR, AND ALL WINDOWS MUST BE ROLLED UP IN WARMER WEATHER TO BLOCK OUT SMELL. I HAVE TAKEN THE VEHICLE TO THE TOYOTA DEALERSHIP, BUT THEY WILL NOT FIX THE PROBLEM BECAUSE THERE IS NO TSB FOR THE V8 (BUT THERE IS FOR THE V6) TOYOTA 4RUNNER. *JB
AFTER 2.5 YEARS AND ABOUT 25000 MILES, MY 4 RUNNER SPORT DEVELOPS A STRONG SULFUR ODOR INSIDE THE CABIN WHEN DRIVING. BROUGHT THE CAR TO THE DEALER (CALDWELL TOYOTA) IN WEST CALDWELL, NJ WHO INFORMED ME THE PROBLEM WAS NORMAL AND CAUSED BY THE TYPE OF FUEL USED. CALDWELL TOYOTA HAD NO ANSWER TO MY QUESTION WHY THE PROBLEM SUDDENLY SURFACED AFTER 2.5 YEARS NOR DID THEY OFFER TO FURTHER INVESTIGATE. THE CALDWELL TOYOTA TECHNICIAN COULD NOT EXPLAIN HOW THE SULFUR SMELL FROM THE EXHAUST, WHICH SHOULD BE CONTAINED WITHIN THE ENGINE AND SHOULD ONLY TO BE EXPELLED FROM THE CAR THROUGH THE MUFFLER ENTERED, THE CABIN WHILE DRIVING (SEEMS PHYSICALLY IMPOSSIBLE). THE STRONG SULFUR ODOR INSIDE THE CABIN CAUSES NAUSEA, LIGHT HEADINESS AND GENERAL DISCOMFORT, WHICH DISTRACT ME FROM DRIVING. THIS PROBLEM SHOULD BE INVESTIGATED AS A POTENTIAL CAUSE FOR TOYOTA 4RUNNER ACCIDENTS. *JB
DT*: THE CONTACT STATED WHILE DRIVING AT ANY SPEED OR EVEN PARKED WITH THE ENGINE RUNNING, THERE WAS STRONG GAS ODOR INSIDE THE CABIN. THE VEHICLE WAS TAKEN TO AN INDEPENDENT CERTIFIED MECHANIC WHO DISCOVERED RUST IN THE INJECTION SYSTEM AND A CATALYTIC CONVERTER FAILURE.
ALMOST CONSTANT SULPHER SMELL. DEALER STATES THAT THEY HAVE NO KNOWLEDGE OF PROBLEM, AND NO TSB'S. THEY TELL ME TO KEEP REAR WINDOW CLOSED. WHEN MY WIFE IS A PASSENGER SHE HAS HER EYES BURNING ALL THE TIME. IF YOU NEED TO STEP HARD ON THE GAS THE WHOLE CABIN FILLS AND IS ENOUGH TO MAKE YOU NOXIOUS. TOYOTA NEEDS TO REMEDY THE PROBLEM ASAP, OR A CLASS ACTION SUIT SHOULD BE FILED. THIS PROBLEM HAS SOURED ME ON TOYOTA PRODUCTS FOR GOOD. LIKE THE VEHICLE BUT HAVE A HARD TIME CINVICING MY WIFE TO GO ANYWHERE IN IT, SHE ALWAYS WANTS TO TAKE HER KIA SORENTO, MORE COMFORT AND NICER AMENITIES. 2004 TOYOTA 4-RUNNER V-6 LTD 4X4 NOT ACCEPTABLE UNLESS YOU LIKE SULPHUR SMELL WHILE DRIVING! *NM
UPON ACCELERATION THE EXHAUST EMITS A VERY STRONG ROTTEN EGG SMELL INTO THE CABIN OF THE VEHICLE. THIS ESPECIALLY HAPPENS WHEN THE REAR WINDOW IS LOWERED.
MY 2004 SPORT 4RUNNER HAS A PERIODIC STRONG SULFUR SMELL ONGOING SINCE I BOUGHT THE VEHICLE IN AUGUST. *JB
Showing 1–20 of 35 complaints
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