2021 Hyundai Tucson Engine Problems

URGENT ADD TO OPEN NHTSA COMPLAINT NUMBER: 11776255. On Monday, November 9, 2026, I presented my 2021 Hyundai Tucson to Service Advisor Grant Bode at Napleton Hyundai due to severe engine knocking. I have explicit photographic evidence of the advisor physically inspecting the vehicle's dipstick on the dealership lot and identifying that the engine oil was heavily overfilled past the maximum limit line. Despite this visual confirmation, the dealership issued a fraudulent Repair Order that completely omitted the oil overfill complaint and falsified the vehicle's drop-off timeline (stating 17:00 hours when the car was left at 7:45 AM). I refused to sign this inaccurate documentation and formally text-messaged the service advisor to dispute the omissions; the advisor has refused to reply. The vehicle currently remains parked on the side of the dealership lot overnight in this exact overfilled condition for a cold-start mechanical evaluation on Tuesday morning, November 10, at 7:00 AM. I am alerting the NHTSA to active dealer manipulation and omission of safety defect evidence while an active federal complaint is open.

NHTSA ID

11776854

Incident

Nov 9, 2026

on at least 4 different occasions this vehicle has at highway speeds been taken over by the engine vibration control which places the vehicle into a low power mode fortunately this did not happen while passing a semi other wise I would and my wife would not be alive .each time the vehicle was taken to the dealership and the sensor was replaced. and reset still keeps happening it is not the sensor when I first purchased this car Hyundai sent a letter requesting that they would compensate for taking this vehicle to their test facility to check it out I filled out the the paper work and sent it back wish I had saved copies.this car is a death trap and undriveable I never heard back

NHTSA ID

11776447

Incident

Dec 26, 2024

COMPONENT FAILED: Engine / Powertrain assembly suffering from severe, documented manufacturing internal oil consumption. Available for inspection upon request. SAFETY RISK: My safety was severely put at risk by Napleton Hyundai (2600 Michigan Ave). On XXXX, Service Manager Heliose explicitly instructed me to deliberately drive the vehicle with known severe fluid loss until the engine completely "locked up" and seized on the road so Hyundai would replace it under warranty (Campaign TXXM). Advising a consumer to drive a vehicle until catastrophic engine seizure occurs at high speeds on public highways creates an extreme hazard—risking sudden stalling, loss of control, and major collisions. Furthermore, the dealer falsified a "goodwill" oil test by completely omitting mandatory tamper-evident safety seals on the dipstick and cap, releasing an unverified, unsafe vehicle into traffic. CONFIRMATION/INSPECTION: Severe oil burning was confirmed by Valvoline on XXX, where a fresh oil change ran completely dry within weeks with no external leaks. Napleton Hyundai acknowledged the engine warranty extensions (T6G, TXXM, DTC P132600) on XXX, but held the test hostage behind an unauthorized $1,400 chemical cleaning fee. The car has not been inspected by police or insurance as a crash has been avoided through manual monitoring. The service intake person ([XXX]) put on my invoice oil consumption check. I checked my engine to see if they placed any (Tamper-Evident Sealing) and the technician did not apply security seals, tape, or paint marks to the oil filler cap, dipstick, and drain plug! They fix this so they would not be responsible for my car engine WARNING SYMPTOMS/TIMELINE: Rapid internal oil depletion causing the engine to run dry within a 30-day window. Symptoms started after a routine oil change on XXX. No dashboard warning lamps are active, making the sudden dry engine an invisible, highly dangerous mechanical hazard. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11776255

Incident

Oct 30, 2026

I took my car in to Allen Samuals Hyundai dealership to have the 9C2 recall update completed on May 15th 2026. Ever since then my vehicle has had a rough hesitation or sputtering when driving. On May 18th Hyundai released a statement stating there was an issue with the update completed on the 9C2 campaign. However no resolution at the moment and to allow the car to warm up prior to driving it. I have only had my car for a little over 2 years and maintained everything a responsible car owner should. It only has 90k miles on it and had zero issues at all prior to the 9C2 campaign. I have spoke woth dealer and corporate numerous times nobody can give me a solution nor does it seem that anyone wants to. Since then the campaign has been closed and its almost as if it never existed. I do have an active case open with Hyundai 43228380 however they act as if they dont know anything about it. They are empathetic to the situation but can't really help or give a solution. All I want it my car that had zero issues prior to this update to run properly again. I dont even drive it much anymore for fear that it will mess my engine up.

NHTSA ID

11766298

Incident

May 15, 2026

Engine knock sensor went off and now the engine needs replacement due to faulty cylinder rod.

NHTSA ID

11760640

Incident

Jun 1, 2026

See attached document for complaint.

NHTSA ID

11758305

Incident

Jun 27, 2026

The contact owns a 2021 Hyundai Tucson. The contact stated that while driving at an undisclosed speed, the engine blew. No warning lights were illuminated. There was white smoke coming from the hood of the vehicle. The vehicle was towed to the dealer; however, the vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 7,800.

NHTSA ID

11756204

Incident

Jun 4, 2026

Mileage

7,800 mi

I was driving down [XXX] from my house.My engine light started to flash.I tried to accelerate my car barely went 10 miles an hour.I got Home 2 minutes later.There was major knocking.I had the car towed to [XXX], Hyundai, the only code that is showing up on the diagnostics, is P1326 there is an open class action lawsuit for this exact code. For the rod bearing failure, Hyundai is denying the claim, saying there's a gap in maintenance history on a car. I didn't own yet when I bought the vehicle. It passed a 190 point inspection. There's no way there was anything wrong with this vehicle.I am under fifty thousand miles , and if I was on the highway , it could've been deadly i could not accelerate. No other lights were on in the vehicle, except for the flashing engine light.I have already reported to the better business bureau and they have sent it to arbitration. I have contacted the escalation department for Hyundai.They opened up to separate cases.The agent that was assigned to me didn't even get the code from [XXX], they just denied the claim without it.I have the emails to prove that I had to give it to her. I have.\n All my maintenance history, but as you can see from the text message from XXX Hyundai, they are requesting maintenance for a car that wasn't in my possession yet. They're asking for dates from a year before I had the car, I bought it through EchoPark. I have everyone on my side including fFdelity , as I tried to go through Fidelity and they said they couldn't approve the warranty because of the class action lawsuit against Hyundai for that exact manufacturer malfunction. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11751238

Incident

Jun 23, 2026

The contact owns a 2021 Hyundai Tucson. The contact stated that while driving at an undisclosed speed, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. The check engine warning light was illuminated. The vehicle was driven to the shoulder of the road before being driven to the residence. The contact’s neighbor checked the oil level and informed the contact that the oil pan was empty. The oil level was topped off. The contact stated that the vehicle was not due for an oil change for another 200 miles. The vehicle was towed to the dealer where it was diagnosed with engine failure. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The contact was informed that there was no oil in the oil pan. The contact was informed to provide the vehicle service records. The contact stated that the failure was a manufacturer's failure. The manufacturer was made aware of the failure, and two cases were filed. The failure mileage was approximately 44,807.

NHTSA ID

11749638

Incident

Jun 23, 2026

Mileage

44,807 mi

My car is burning oil. I have returned multiple times to have it serviced and checked for leaks, but no leaks have been found. Before reaching the recommended 3,000-mile oil change interval, the oil level drops below the minimum mark on the dipstick. In addition, my engine has started making a knocking noise, which is very concerning.

NHTSA ID

11743079

Incident

Jan 1, 2026

Vehicle stalled approximately 15 times between April 17 and May 4, 2026, including once on Interstate XXX at approximately 50mph with minor children ages [XXX] and [XXX] in the vehicle. The oil and battery lights illuminated simultaneously at each stall. Diagnosed as ABS module failure first, then left front wheel speed sensor failure on the 2nd occasion, both confirmed by a Hyundai dealership. Multiple warning lights illuminated, including check blind spot and anti lock brake system messages on the dashboard BUT no error codes following the 2nd repair. The vehicle has been inspected and repaired twice by the manufacturer’s dealership with a 3rd repair currently pending as of May 11, 2026. An open case has been filed with Hyundai Motor America regarding this issue. Issue remains unresolved and the vehicle is still at the dealership. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11737345

Incident

Apr 17, 2026

2 years ago I had the engine replaced. Now on this new engine which has approximately 29k. The mechanic is telling me that I need a new engine. I called Hyundai and their telling me that is not under warranty anymore. What can be done?

NHTSA ID

11736406

Incident

May 7, 2026

My 2021 Hyundai Tucson has experienced repeated engine-related failures associated with a knock sensor (P1326) fault that causes the vehicle to enter limp mode and lose power while driving. This issue has occurred multiple times at approximately 15,000, 17,000, 41,000, and 90,000 miles and has resulted in four separate incidents requiring towing. During these events, the vehicle suddenly loses power and cannot maintain normal driving speed, creating a hazardous condition while in traffic. The vehicle has undergone multiple repair attempts, including an ECM update and three knock sensor replacements. Despite these repairs, the issue continues to recur and no root cause has been identified. Hyundai has not provided a permanent fix and has advised continued operation of the vehicle unless the issue occurs again. This ongoing condition presents a safety concern due to the risk of sudden loss of power while driving.

NHTSA ID

11735611

Incident

Mar 16, 2026

I already replaced 3 catalytic converters and I am at 31000 miles. They finally decided to do an oil consumption test but it passed. The other day my car started shaking and my ignition coil and spark plugs were also bad which somehow is related to my engine issues.

NHTSA ID

11727243

Incident

Oct 20, 2022

The contact owns a 2021 Hyundai Tucson. The contact stated that while driving at various speeds, the check engine warning light was frequently illuminated on the instrument panel. The contact had taken the vehicle to various independent mechanics and was informed that the engine was consuming an excessive amount of engine oil. The contact had taken the vehicle to a dealer for service, and upon inspection, the contact was informed that the engine needed to be replaced. The contact was provided with an estimate for the engine replacement. The manufacturer was notified of the failure but offered no assistance. The contact was initially informed that the vehicle was covered under warranty; however, the contact was later informed that there was no warranty on the vehicle. The vehicle was not yet repaired. The failure mileage was approximately 89,000.

NHTSA ID

11726305

Incident

Jan 1, 2025

Mileage

89,000 mi

While driving on the freeway, my 2021 Hyundai Tucson SE (72,021 miles) suddenly and without warning lost power and entered limp mode. I was able to safely maneuver to the shoulder and exit the freeway. The check engine light came on and is currently flashing. I took the vehicle to AutoZone where code P1326 was retrieved. I then took it to Pep Boys for a full diagnostic where P1326 was the only code present. The Pep Boys report states the vehicle requires immediate attention. The vehicle remains in limp mode and the check engine light is flashing. The vehicle is not being driven as it cannot safely reach freeway speeds. I contacted Hyundai Customer Care and was assigned Case # XXX. I also contacted a Hyundai dealership who attempted to charge a $225 diagnostic fee despite P1326 being a known Hyundai defect covered under recall/service campaign. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11724214

Incident

Mar 13, 2026

The vehicle experienced a catalytic converter efficiency failure that was confirmed by an authorized dealership in January 2025. The dealer indicated the catalytic converter required replacement; however, the replacement was not performed, and the vehicle was returned to service with an unresolved emissions defect. Less than one year later, the vehicle developed recurring emissions system failure, loss of power, drivability issues, and repeated warning indicators. The vehicle is currently out of service while additional components, including oxygen sensors and spark plugs, are reported to be affected. The manufacturer is declining to replace the catalytic converter and is attributing the condition to oil consumption despite the prior unresolved emissions failure. The issue has been confirmed by dealership diagnostics and has resulted in prolonged loss of use of the vehicle. This appears to be a continuing engine and exhaust/emissions system defect that was not properly remedied when first identified and may affect safe operation of the vehicle.

NHTSA ID

11716729

Incident

Jan 10, 2025

The contact owned a 2021 Hyundai Tucson. The contact stated that while driving at 10 MPH, an abnormal clicking sound was coming from under the hood. No warning lights illuminated. In addition, the contact managed to pull over to the shoulder of the road, where white smoke was noticed leaking from under the hood, and the intensity was increasing while the smoke turned black. The local fire department arrived on scene to extinguish the fire. The source of the fire was not identified. It was unknown if a Fire report was filed. A police report was filed. No injuries were sustained, and medical attention was not sought. The vehicle was towed to the contact's residence. The vehicle was deemed a total loss as it was majoily consumed by the fire. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 65,000.

NHTSA ID

11715856

Incident

Feb 3, 2026

Mileage

65,000 mi

I have been adding oil to this engine excessively for more than 3 years..I have had appointments with the dealer where they flat out told me bring it back when the engine fails.i finally got N appointment and was told the engine needed to be replaced.that was 2 weeks ago..they are now denying the claim...have had my car for 2 weeks..no loaner..and decided to deny what they told me

NHTSA ID

11712752

Incident

Jan 17, 2026

The contact owned a 2021 Hyundai Tucson. The contact stated that immediately after purchasing the certified vehicle, the vehicle went into LIMP Mode while her grandson was driving approximately 65 MPH, and the vehicle decelerated to 7 MPH. The vehicle was towed to the local dealer who diagnosed that the NOX sensor had failed and needed to be replaced. The vehicle was repaired but while leaving the dealer, the failure reoccurred. The vehicle was towed back to the dealer who replaced a second NOX sensor and the catalytic converter. The contact stated that days after retrieving the vehicle, the failure reoccurred, and the vehicle was towed back to the dealer who diagnosed that the NOX sensor had failed for a third time, within several days of owning the vehicle. The vehicle was traded in. The manufacturer was notified of the failure. The failure mileage was 28,944.

NHTSA ID

11712627

Incident

Nov 27, 2025

Mileage

28,944 mi

I am the original owner of this car and in June 2025 I brought my car to Hyundai from noises and they told me it had no oil despite me being up to date with oil changes on the vehicle. They told me they were going to do an oil consumption test and once they did that the engine was denied. 6 months later 3 days after an oil change and no check engine light on, the engine fails while I’m on the side of the highway. This car is not safe. Check engine light was not on and I am always up to date with my cars maintenance.

NHTSA ID

11709985

Incident

Dec 26, 2025

Oil Consumption problems

NHTSA ID

11709979

Incident

Aug 1, 2024

Oil light comes on between changes at about 1500 miles before needing one, oil does not show on dipstick and have to repeatedly put on in engine. Chance of engine seizing or jumping time.

NHTSA ID

11706731

Incident

Dec 23, 2025

We were driving and the engine light started flashing and buckling. The vehicle had been properly maintained with oil changes. We have oil changes receipts from our mechanic. Hyundai refuses to cover it under their warranty even though there are documented issues with the make and models of 2021 Hyundai Tuscons.

NHTSA ID

11699481

Incident

Aug 9, 2025

Engine started making a knocking sound, then the oil light came on followed by the check engine light. Accelerates and decelerates on its own. Was forced to immediately pull over across three lanes on Interstate 95. It’s been over two weeks and I’ve yet to hear if Hyundai is going to cover a replacement engine. However, what happened is exactly what they have listed on their website ⬇️ What to look out for check-engine Check Engine oil-light Engine Oil Pressure A knocking noise from the engine that increases in frequency as the engine rpm increases. Reduced power and/or hesitation and vibration. Illumination of the “check engine” light in the instrument cluster. Illumination of the “engine oil pressure” warning lamp.

NHTSA ID

11697532

Incident

Oct 22, 2025