Engine knock sensor went off and now the engine needs replacement due to faulty cylinder rod.
2021 Hyundai Tucson
Owner reports · Recalls · Investigations
Similar to other model years
Owner complaints for the 2021 Hyundai Tucson do not stand out strongly from the model-year median of 180.5.
About this comparison →How this year compares
Owner complaints by model year
Compare all Tucson years →Counts vary with age, sales and reporting. They are not failure rates.
What owners reported most
All reported categories
Tap a category to read its complaints. One report may name several components.
When problems were reported
Mileage at the reported incident
Limited mileage data: 14 of 78 reports include usable mileage. There isn’t enough coverage to show a useful chart.
NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.
What to inspect
Issues worth paying extra attention to based on owner reports.
- Engine. Review the 38 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Electrical System. Review the 11 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Service Brakes. Review the 9 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
NHTSA owner reports · September 18, 2026 snapshot.
Engine complaints
38 reportsThe 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 m…
Read full complaint
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.
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 …
Read full complaint
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)
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…
Read full complaint
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.
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 conce…
Read full complaint
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.
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…
Read full complaint
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)
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?
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 incident…
Read full complaint
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.
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.
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 …
Read full complaint
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)
Official recalls
120V543000 · Service Brakes, Hydraulic:antilock/traction Control/electronic Limited Slip:control Unit/module
Sep 4, 2020
Hyundai Motor America (Hyundai) recalled certain 2019-2021 Tucson vehicles on September 4, 2020. On December 30, 2020, Hyundai expanded the recall population, and added certain 2016-2018 Tucson vehicles. The Anti-lock Brake Hydraulic Electronic Control Unit (HECU) could corrode internally and cause an electrical short, possibly resulting in an engine compartment fire.
Consequence & remedy
Consequence: An engine compartment fire can increase the risk of injury or crash.
Remedy: Hyundai will notify owners, and dealers will replace the HECU fuse. For 2019-2021 model years, the Electronic Stability Control (ESC) software will also be updated. Recall repairs will be performed free of charge. Owners are advised to park outside and away from structures as a precaution until the recall repair is complete. The recall began November 2, 2020. Owners may contact Hyundai customer service at 1-855-371-9460. Hyundai's number for this recall is 195.
Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗
NHTSA investigations
1AQ23002 · Hyundai And Kia Abs Module Fires
Opened Nov 17, 2023 · No close date supplied
Status: open (inferred from source dates) · Service Brakes, Hydraulic:antilock/traction Control/electronic Limited Slip:control Unit/module
The Office of Defects Investigation (ODI) has received eight Hyundai Motor America (Hyundai) and eight Kia America, Inc. (Kia) Part 573 Recall Reports between 2016 and 2023. The combined 16 safety recalls all involve the antilock braking system (ABS) modules or Hydraulic Electronic Control Units (HECU) manufactured by the equipment supplier Mando. The Part 573 Recall Reports contain varying defect descriptions and differing remedy descriptions for the same or similar equipment supplied by Mando. Safety recalls included in this Audit Query (AQ) review include: Hyundai recalls 20V-520, 20V-543, 21V-161, 21V-160, 21V-303, 22V-056, 22V-810, and 23V-651. Kia recalls 16V-815, 20V-518, 20V-519, 21V-137, 21V-331, 22V-051, 22V-800, and 23V-652 The purpose of this AQ is to evaluate the timeliness and scoping of Hyundai and Kia’s defect decision making and adherence with reporting requirements; and understand the varying defect descriptions and remedies between these recalls.
Illustration