2006 Hyundai Sonata Engine Problems

The contact owns a 2006 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the vehicle experienced a loss of automotive power. No warning light was illuminated. The contact was able to pull over to the shoulder of the roadway and noticed that engine oil was leaking onto the ground and the coolant level was abnormally low. The contact stated that the vehicle failed to restart and was towed to a local independent mechanic, where it was diagnosed with a valve cover leak. The vehicle was repaired at the owner's expense; however, the failure reoccurred. The local dealer was not contacted. In addition, the contact stated that several other unknown repairs were made; however, the failure reoccurred. The contact related the failure to an unknown NHTSA Campaign; however, the VIN was not included. The manufacturer was made aware of the failure. The failure mileage was approximately 112,000.

NHTSA ID

11706449

Incident

Nov 20, 2025

Mileage

112,000 mi

I am filing this complaint regarding a serious engine issue with my 2006 Hyundai Sonata equipped with a 2.4L GDI engine. My vehicle experienced [engine knocking, stalling, and then seized up indicating complete Engine failure] without warning, posing a potential safety hazard while driving. The issue appears to be identical to the known manufacturing defects that Hyundai has acknowledged in its recall of 2013–2014 Sonata models with the same engine Class Type. Although my vehicle is not currently included in the official recall “ SONATA ENGINE RECALL CAMPAIGN it contains the Theta II MPI Engine which constitutes and Further solidifies proof of the ongoing Manufacturing Defects of Theta Model Engine design and exhibits the same symptoms of sudden engine failure. This raises concerns that the defect may affect a broader range of model years than Hyundai has acknowledged. I urge NHTSA to investigate this issue and determine whether the scope of the current recall should be expanded to include earlier model years such as 2006. The defect creates a significant safety risk to drivers and passengers, and Hyundai should be held accountable for all affected vehicles—not just those produced within a narrow window.

NHTSA ID

11663025

Incident

May 16, 2025

UNKNOWN

NHTSA ID

11526092

Incident

Aug 20, 2022

MY SON WAS DRIVING AND HEARD LOUD POP AND SAW FLAMES COMING FROM HOOD FIRE DEPARTMENT PUT OUT FIRE CAR IS COMPLETE LOSS

NHTSA ID

11523016

Incident

May 19, 2023

May 2019: Battery light came on and off for a few minutes. Car sputtered and engine quit. Replaced alternator and battery; problem went away. Feb 2022: Battery light came on and off for a few minutes. Car sputtered and engine quit. Replaced alternator and battery. This time the mechanic noticed that oil was leaking from the front valve cover gasket and was getting into the alternator; thus the most likely source of damage to alternator.

NHTSA ID

11451574

Incident

Feb 2, 2022

DRIVING ON THE HIGHWAY AND MY CAR JUST DIED OUT OF NO WHERE TOOK IT TO GET LOOKED AT ONLY TO FIND OUT THE ENGINE DIED CAR GOT SO HOT IT HAD TO SIT OVER NIGHT TO COOL. ALSO WAS DRIVING ONE DAY AND ROOK A TURN AMD MY BRAKES WOULDN'T STOP TOOK IT IN AND FOUND OUT THE ENTIRE BRAKE LINE WAS CORRODED HAD TO SPEND THOUSANDS TO GET IT FIXED.

NHTSA ID

11376901

Incident

Aug 7, 2020

MY VEHICLE WAS MOVING UPON COMING TO A STOP. I TRIED THE BRAKE SYSTEM BUT MY CAR WOULDN'T STOP AND CAUSED AN ACCIDENT. THAT'S WHAT I REMEMBER.

NHTSA ID

11288604

Incident

Feb 17, 2019

I HEARD REALLY LOUD SOUND IN THE ENGINE BUT THERE'S NO CHECK ENGINE LIGHT. AFTER OF FEW DAYS OF DRIVING AND THE DAY I DECIDED TO BRING IT TO THE MECHANIC, FEW MILES AWAY FROM THE SHOP THE THE LOUD NOISE IN THE ENGINE IS GONE THEN CHECK ENGINE SHOW UP AND THE OIL PAN APPEARS. THE MECHANIC SAID IT WAS THE OIL PUMP AND THEY SAID THERE'S A METAL SHAVING INSIDE THE ENGINE, WHEN THEY DRAIN THE ENGINE OIL.

NHTSA ID

11255722

Incident

Aug 9, 2019

THE BRAKES ON MY 2006 HYUNDAI SONATA FAILED ON ME AS I WAS DRIVING. MY CAR SEEMED TO HAVE NOT BEEN WORKING PROPERLY.

NHTSA ID

11184493

Incident

Feb 17, 2019

Mileage

211,000 mi

TL* THE CONTACT OWNED A 2006 HYUNDAI SONATA. WHILE DRIVING HIGHWAY SPEEDS, THE VEHICLE MADE AN ABNORMAL NOISE AND SMOKE EMITTED FROM THE ENGINE COMPARTMENT. THE FAILURE OCCURRED WITHOUT WARNING. THE CONTACT WAS ABLE TO SAFELY MANEUVER FROM THE HIGHWAY TO A PARKING LOT. THE CONTACT EXITED THE VEHICLE AND OBSERVED FLAMES UNDERNEATH THE VEHICLE. THE FIRE DEPARTMENT WAS CONTACTED AND EXTINGUISHED THE FIRE. THE VEHICLE WAS TOWED TO A SALVAGE YARD WHERE IT WAS DEEMED A TOTAL LOSS. THE DEALER AND MANUFACTURER WERE NOT NOTIFIED. THERE WERE NO INJURIES. THE CONTACT STATED THAT THE VEHICLE WAS INCLUDED IN NHTSA CAMPAIGN NUMBER: 18V026000 (SERVICE BRAKES, HYDRAULIC). THE FAILURE MILEAGE WAS APPROXIMATELY 100,000.

NHTSA ID

11114927

Incident

Jul 14, 2018

Mileage

100,000 mi

THE CHECK ENGINE LIGHT STARTING GOING ON AND OFF. OUR 19-YEAR-OLD DAUGHTER WAS DRIVING ON THE FREEWAY AT NIGHT WHEN THE LIGHT CAME ON AND IT STARTED MAKING A LOUD NOISE. SHE STOPPED ON THE SIDE OF THE FREEWAY, TURNED IT OFF AND NEVER COULD RESTART IT. THE ENGINE DIED. IT BLEW A ROD. THE CAR HAD REGULAR MAINTENANCE. WE HADN'T HAD ANY WORK DONE RECENTLY THAT COULD HAVE LED TO ENGINE PROBLEMS. THE MECHANIC SAID IT HAD OIL AND HE COULDN'T EXPLAIN WHAT HAPPENED.

NHTSA ID

11080978

Incident

Feb 15, 2018

Mileage

136,861 mi

CAR HYUNDAI SONATA V6 2006 STARTED DEVELOPING ENGINE NOISE WHEN I WAS DRIVING IT IN MY PARKING LOT AFTER I MADE A TURN.. CYCLIC NOISE SIMILAR TO THE ONE MENTIONED IN HTTPS://WWW.CONSUMERREPORTS.ORG/CRO/CARS/HYUNDAI-SONATA-ENGINE-FAILURES-PROMPT-RECALL IT HAS 104000 MILES AND IS NOT LOW ON OIL. MECHANIC SAYS ENGINE HAS TO BE REPLACED.. IT'S NOISE FROM INSIDE THE ENGINE AND DANGEROUS TO DRIVE WITH IT.

NHTSA ID

11065346

Incident

Jan 5, 2018

Mileage

104,000 mi

IT IS HAVING THE SAME PROBLEMS THAT THE ENGINES ARE BEING RECALLED FOR NOW. IT IS MAKING TAPPING AND PINGING SOUNDS. I HAVE LOOKED THE VEHICLE AND HAVE SEEN PEOPLE HAVE BEEN COMPLAINING ABOUT THEIR 2006 HYUNDAI SONATAS DOING THE SAME THING. SCRAP YARDS HAVE THESE CARS THERE WITH BLOWN ENGINES. MY SON IS HAVING TO PAY ON A LOAN ON A CAR THAT HE CAN NOT EVEN DRIVE. WE HAVE CALLED THE BANKS AND INSURANCE. IT WILL COST MORE TO FIX THE ENGINE THAN WHAT HE OWES. WHY ARE 2006'S NOT BEING RECALLED ALSO?

NHTSA ID

10979283

Incident

Feb 1, 2017

MY WIFE AND I PURCHASED THE VEHICLE ON 10/11/2016 AT J.D. BYRIDER OF MANSFIELD AND NOTICED THAT THERE WAS A CLICKING TYPE SOUND WHEN STARTING VEHICLE. ON 10/14/2016 WHILE MY WIFE WAS LEAVING WORK SHE WENT TO TURN THE VEHICLE AND IT WAS VERY HARD BUT MANAGED TO GET HOME AND WOKE ME UP, I THEN WENT OUT AND VIEWED THAT THE SERPENTINE BELT WAS VERY LOOSE AND THAT THERE WAS A PULLEY LAYING BY THE ENGINE; JD BYRIDER FIXED THE ISSUE OF PULLEY AND BELT; AFTER WE RECEIVED THE VEHICLE BACK WE NOTICED THAT THE CLICKING TYPE NOISE WAS STILL THERE.

NHTSA ID

10925486

Incident

Oct 14, 2016

Mileage

87,260 mi

PURCHASED THIS SONATA USED 3 MONTHS AGO WITH 45,800 MILES ON IT, DROVE IT 4,000 MILES AND IT DEVELOPED A ENGINE TICKING NOISE WHICH NOW HAS TURNED INTO A KNOCKING SOUND AT 1800 RPMS GOES AWAY, THEN COMES BACK AT 2200 RPMS. I CONTACTED HYUNDAI CUSTOMER SERVICE TO ESTABLISH A CASE NUMBER. THE DEALER HAS REMOVED THE OIL PAN AND FOUND SHAVINGS SAYING IT NEEDS A "SHORT BLOCK" MOTOR REPLACEMENT AT A COST OF $5,800. HYUNDAI MOTOR AMERICA DENIED THE REQUEST FOR REPAIR TOTALLY. I FIND THAT AT 50,000 MILES AND BEING ONLY THE SECOND OWNER, THIS MOTOR HAD A DEFECT THAT SHOULD BE ACKNOWLEDGED AS A DEFECT AND THEY SHOULD STAND BEHIND THERE PRODUCT! THIS IS MY THIRD HYUNDAI, NEW 2005 AND NEW 2007 AND I'M SERIOUSLY IN THE MARKET FOR A NEW SUV BUT IF HYUNDAI WON'T STAND BEHIND A COSTLY DEFECT LIKE THIS THEY WILL LOOSE A 10 YEAR VERY LOYAL CUSTOMER FOREVER.

NHTSA ID

10894861

Incident

Aug 2, 2016

Mileage

50,000 mi

WHILE DRIVING, THE DAMPER PULLEY SEPERATES AND THE POWER STEERING FAILS ALONG WITH THE WATER PUMP AND THE ALTERNATOR. THIS DAMPER AS IT IS CALLED IS A DEVICE THAT DRIVES ALL THE BELT POWERED DEVICES ON THE ENGINE. I ASKED THE DEALER IF THERE WAS A RECALL ON THIS AND THE REPLY WAS NO. HOW CAN A POWER STEERING FAILURE NOT BE A RECALL? WHEN YOU ARE TURNING AND THE POWER STEERING FAILS I WOULD SAY THE MAJORITY OF DRIVERS WOULD NOT BE ABLE TO STEER THE VEHICLE OUT OF THIS SITUATION. LOOK ONLINE AND VIEW ALL THE PLACES THAT LIST THIS PROBLEM. THIS IS A BIG SAFETY ISSUE THE VEHICLE STEERS VERY HARD AND IS DIFFICULT TO CONTROL.

NHTSA ID

10885211

Incident

Jul 14, 2016

Mileage

32,564 mi

WHEN I START UP MY CAR MY CAR SOUNDS LIKE IN GRINDS THEN IT STOPS ITS THE CHAIN TENSIONER REPLACEMENT

NHTSA ID

10863306

Incident

Dec 16, 2015

VEHICLE WAS IN MOTION ON CHICAGO CITY STREETS AND TEMP GAUGE STARTED TO RISE SLOWLY AND I BEGAN SMELLING ANITFREEZE. LATER THE TEMP GAUGE ROSE SIGNIGIGANTLY THE ANTIFREEZE BEGAN LEAKING HEAILY FROM BENEATH AND SMOKE BEGAN RISING FROM UNDER THE HOOD VERY HEAVILY. UPON AUTO SHOP INSPECTION THE REPAIRMAN NOTICED THAT THE SMOKE WAS COMING FROM AN AREA BY THE ENGINES' HEATING CORE RUBBER HOSES. THE REPAIRMAN REMOVED THE HEATING CORE RUBBER HOSES FOR INSPECTION AND FOUND THAT THE ENGINES' HEATING CORE METAL TUBING NOSLES/NIPPLES APPEARED AS THOUGH THEY HAVE BEEN DIPPED IN ACID. THE REPAIRMAN CONCLUDED THAT HEATER CORE METAL TUBING NOSLE/NIPPLES SEVERE CORROSION IS NOT NORMAL WEAR OR TEAR OR A COMMON AUTOMOBILE PROBLEM.

NHTSA ID

10862336

Incident

Apr 26, 2016

Mileage

118,500 mi

MY SONATA 3.3L V-6 ENGINE WITH WHAT APPEARS TO BE A VERY COMMON AND DANGEROUS PROBLEM. THIS VEHICLE SEEMS TO BEGIN STALLING AND SLAMMING INTO 3RD GEAR FAIL SAFE MODE, LUCKILY I HAVE NOT BEEN REAR-ENDED DUE TO THIS YET! I HAVE READ UP EXTENSIVELY ON THIS AND FOUND MANY WITH THE SAME COMPLAINT ON WWW.CARCOMPLAINTS.COM WEBSITE. IT APPEARS MANY DEALERSHIPS ARE AWARE AS THEY HAVE HAD VEHICLE IN TO BE PROBLEM SOLVED WITH WHAT APPEARS TO BE AN ELECTRICAL PROBLEM MORE SO THAN A MECHANICAL PROBLEM. AFTER HAVING MY CAR INTO 4 DIFFERENT SHOPS INCLUDING A DEALERSHIP THE FIRST TIME IT HAPPENED WITH NO FIX AND ONLY A 'IF WE CAN'T REPLICATE THE PROBLEM WE CAN'T FIX IT' RESPONSE I GET MAD. WE HAVE RULED OUT EVERYTHING POSSIBLE; TRANSMISSION, ENGINE, RELAYS, ETC. FOR 4 MONTHS IT HAS BEEN IN AND OUT OF SHOPS TRYING TO DIAGNOSE THE PROBLEM. WHICH IS HAPPENING SO OFTEN NOW IT IS NOT SAFE AND I AM HAVING TO TAKE OUT A LOAN TO TRY AND BUY A NEW CARE. I CANNOT TRADE THIS IN DUE TO THE PROBLEM. WHEN IT IS RUNNING IT RUNS GREAT, UNTIL IT SLAMS INTO 3RD GEAR WITH NO WARMING AND YOU LOOSE ALL ACCELERATION OR IT DIES COMPLETELY. YOU CAN SHUT IT OFF AND RESTART IT AND IT RUNS AS IF NOTHING HAPPENED, UNTIL IT STALLS AGAIN. THE LAST MECHANIC HAVING VERIFIED EVERYTHING HE WAS TOLD TO CHECK HAS DETERMINED IT MUST BE IN THE COMPUTER. SOME INDIVIDUALS SAID EARLY ON THEY HAD THE COMPUTERS REPLACES (AT A BIG COST) ONLY TO HAVE IT HAPPEN AGAIN. MY CAR IS 10 YEARS OLD AND ONLY HAS 118,000 MILES ON IT. I HATE HAVING TO GET RID OF THIS CAR BUT THERE IS NO WAY IT IS SAFE TO DRIVE IN THIS CONDITION. HYUNDAI SEEMS TO BE IGNORING THIS COMPLAINT AS NO RECALL HAS BEEN ISSUED AND NO HELP IN REPAIRING THE PROBLEM. TOO MANY CARS AT THE APRX MILEAGE WITH THE SAME PROBLEM AND LEADS ME TO BELIEVE A RECALL IS IN ORDER OR FINANCIAL REIMBURSEMENT FOR THE MONTHS OF REPAIR TO FIX IT SHOULD BE MADE. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). *TR

NHTSA ID

10862176

Incident

Jan 8, 2016

Mileage

85,000 mi

FIRST, OIL IS LEAKING ON ALTERNATOR AND AREA AROUND, CAR NEEDS A VALVE COVER GASKET, DRIVER AIRBAG LIGHT STAYS ON, PASSENGER SUN VISOR WONT STAY UP, THE VEHICLE HAS 149000 MILES ON IT. THERE ARE TO MANY COMPLAINTS FOR THESE SUBJECTS, A RECALL NEEDS TO BE ISSUED.

NHTSA ID

10851692

Incident

Mar 18, 2016

ON LAMBDA/LAMBDA II MPI SERIES ENGINES, ENGINE OIL CAN LEAK ONTO THE ALTERNATOR, WHICH COULD AFFECT CHARGING SYSTEM FUNCTION AND POTENTIALLY CAUSE THE ENGINE TO STALL AND NOT RESTART. THIS WOULD RESULT IN A LOSS OF MOTIVE POWER AS WELL AS AFFECT POWER BRAKING AND POWER STEERING SYSTEM FUNCTION, WHICH WOULD UNEXPECTEDLY INCREASE STEERING AND BRAKE PEDAL EFFORT, POTENTIALLY INCREASING STOPPING DISTANCES AND THE RISK OF A CRASH CAUSING INJURY AND/OR DAMAGE TO PROPERTY. EVERY MAKE/MODEL OF VEHICLE THAT HAS THIS ENGINE HAS OIL LEAKS ON THE ALTERNATOR AND OTHER CRITICAL COMPONENTS (I'VE REPLACED 3 ALTERNATORS SO FAR! ~$200 EACH! + LABOR!!!) YET ONLY A CERTAIN YEAR OF THE "VERA CRUZ" RECEIVED A RECALL BECAUSE THE COST TO HYUNDAI WOULD BE HIGHER TO FIX THIS ISSUE ON ALL AFFECTED VEHICLES (AZERA, SANTE FE, AND MY SONATA ETC. MODELS)

NHTSA ID

10823964

Incident

Nov 20, 2015

Mileage

40,000 mi

I OWN A 2006 HYUNDAI SONATA, AT 100,000 (HWY MILES) THE FRONT UPPER CONTROL ARMS BECAME SQUEEKY AND DETATCHED FROM THE RUBBER BUSHINGS, MAKING A HORRIBLE RIDE AND CLUNKING SOUND WHEN I WOULD PUT THE CAR INTO GEAR. THIS PROBLEM MAKES THE CAR BOUNCY AND UNSTABLE. THERE IS ALSO A KNOCKING OR LOUD CLICKING SOUND IN THE ENGINE AT CRUSING SPEEDS, WHEN I BARLEY PUSH THE GAS PEDAL. IT SOUNDS LIKE THE AIR INTAKE CONTROL VALVE. IT GOES AWAY WHEN I ACCELERATE. THE RADIO AND CRUISE CONTROL ELECTORNICS SEEM TO WORK ONLY WHEN THEY WANT TOO!

NHTSA ID

10810717

Incident

Dec 10, 2012

Mileage

100,000 mi

OIL LEAK FROM ENGINE VALVE COVER - LEFT (FRONT) SIDE OF 3.3 V6. THIS IS DIRECTLY ABOVE ALTERNATOR. EVENTUALLY ALTERNATOR FAILS DUE TO SEVERE OIL/DIRT CONTAMINATION. FIRST NOTICED WHEN BATTERY LIGHT COMES ON AT IDLE, SHOWING CHARGING PROBLEM. BY THEN DAMAGE IS DONE. VALVE COVER MUST BE REPLACED ALONG WITH ALTERNATOR OR PROBLEM WILL QUICKLY RECUR. *THERE IS CURRENTLY A RECALL FOR HYUNDAI VERACRUZ WITH SAME ENGINE FOR THE SAME PROBLEM. SONATA IS NOT INCLUDED, BUT A QUICK INTERNET SEARCH SHOWS THIS TO BE A COMMON, WELL-KNOWN PROBLEM FOR MANY YEARS.

NHTSA ID

10789010

Incident

Nov 1, 2015

Mileage

100,000 mi

2006 HYUNDAI SONATA. CONSUMER WRITES IN REGARDS TO REPLACEMENT OF DRIVE BELT ISSUES. *SMD THE CONSUMER STATED THERE WERE NO ISSUES WITH THE VEHICLE, PRIOR TO THE DRIVE BELTS BEING REPLACED. A FEW WEEKS AFTER THE BELTS WERE REPLACED, THE VEHICLE WAS NOT PERFORMING WELL WHEN DRIVEN. THERE WAS HARDNESS ON THE ACCELERATOR PEDAL, THERE WAS A SLIGHT, FAINT CHIRPING, FAINT GRINDING SOUND WHEN THE A/C WAS TURNED ON. THE MANAGER INFORMED THE CONSUMER, THE NOISE WAS COMING FROM THE A/C/PANEL AND MAYBE A LOOSE FLAP. HOWEVER, THE NOISE CONTINUED. THE VEHICLE WAS RETURNED TO THE MECHANIC, WHO INSPECTED THE VEHICLE AND DISCOVERED THE BELT THAT WAS INSTALLED WAS NOT THE CORRECT ONE FOR THE VEHICLE. HOWEVER, AFTER THE ORIGINAL BELT WAS INSTALLED THE NOISE WAS STILL PRESENT, BUT NOT AS LOUD. ALSO, THE STRUTS WERE REPLACED DUE TO HEARING A NOISE WHEN GOING OVER BUMPS.*JB

NHTSA ID

10677136

Incident

Sep 4, 2014

IN JAN. 2015 IT WAS ON A 100 MILE HIGHWAY TRIP. UPON ARRIVAL HE NOTICED THE ENGINE DEVELOPED A KNOCKING NOISE. I FOUND MANY 2.4L HYUNDAI'S WITH THE SAME PROBLEM ON THE INTERNET. THE ENGINE WAS MADE IN INDIANA. IT SOUNDS THE SAME AS NHSTA CAMPAIGN #15V-568. IT NEEDS A NEW ENGINE. I CAN'T UPLOAD IT, BUT I HAVE VIDEO OF THE KNOCKING. I BELIEVE THE RECALL NEEDS TO BE EXPANDED TO EARLIER YEARS

NHTSA ID

10785730

Incident

Jan 9, 2015

Mileage

105,000 mi