2021 Lincoln Nautilus

On July 22, 2022, the Office of Defects Investigation (ODI) granted a Defect Petition (DP22001) and opened a Preliminary Evaluation (PE22007) to investigate allegations of loss of motive power in model year (MY) 2021 Ford Bronco vehicles equipped with 2.7L EcoBoost engines. Complainants were reporting sudden engine failure while driving resulting in a loss of motive power, often without the ability to restart. During PE22007, the cause of engine failure and loss of motive power in the subject vehicles was determined to be intake valve fracture, and the full scope of vehicles affected by the subject defect was identified as all MY 2021-2022 Ford and Lincoln models equipped with either the 2.7L or 3.0L EcoBoost engines, referred to as the “Nano” engine family.  If an intake valve fractures in the subject engines, it may drop into the cylinder and contact the piston, often resulting in catastrophic engine damage. On September 29, 2023, PE22007 was upgraded to an Engineering Analysis (EA23002) to further investigate the subject defect across the full scope of affected vehicles. During EA23002, ODI visited Ford facilities to review technical information related to intake valve fracture in “Nano” engines, coordinated with NHTSA’s Vehicle Research and Testing Center (VRTC), and analyzed updated field data relating the subject defect. Forensic analysis of fractured intake valves demonstrated that the defective components exhibited “grinding burn” or out of specification hardness in the area of the keeper grooves. The presence of grinding burn is evidence that during the groove grinding phase of production, the temperature of the valve became sufficiently high to alter the microstructure of the material and is indicative that the valve supplier’s manufacturing processes were not within control specifications. Grinding burn results in a hard, brittle microstructure and high residual stresses toward the surface of the valve. Through normal engine loading, a valve with grinding burn will likely fracture at the area of highest vulnerability, which is the third keeper groove. In its response to the EA23002 Information Request (IR) letter, Ford provided evidence of 396 customer complaints (including field reports), 825 warranty claims, and 936 engine exchanges. When considering both ODI and manufacturer failure report data, there have been reports representing 1066 unique vehicles within the subject vehicle population. Analysis of the failure report data demonstrates that vehicles equipped with potentially defective intake valves were built within a production “spike period” of May 2021 – October 2021. The beginning of the spike period corresponds to a ramp up in production at the valve supplier manufacturing facility, and the end of the spike period aligns with the implementation of several mid-production process improvements and the decision to change the metal alloy used to produce intake valves from “Silchrome Lite” to “Silchrome 1”. Ford began investigating the subject defect in July 2021, determined the root cause, and took corrective measures for the new production vehicles. Analysis of the failure report data demonstrates that these corrective actions were successful in eliminating the risk of intake valve fracture for subject vehicles produced after October 2021. However, Ford did not take any field action to address vehicles produced during the spike period, and in the several months following the implementation of the production changes, a significant number of field failures continued to occur. It is Ford’s assessment that not all valves produced during the spike period are defective, and that failures associated with the subject defect occur at low time in service. Analysis of the failure report data demonstrates that the vast majority of failures have occurred before 20,000 miles with over half of all reported failures occurring before 5,000 miles. The rate of reported failures related to the subject defect has steadily decreased since November 2021. ODI coordinated with NHTSA’s National Center for Statistics and Analysis (NCSA) to conduct statistical analysis and predict the number of future failures associated with the subject defect. The results of this analysis, and the trends identified through the failure report data are generally consistent with Ford’s assessment that defective intake valves will likely fail at a low time in service and indicate that the majority of subject vehicles equipped with defective valves have already experienced a failure. On August 23, 2024, Ford submitted recall 24V635 for subject vehicles equipped with “Nano” engines and built within the production spike period identified above (total population 90,736 vehicles). The remedy includes an inspection at a Ford/Lincoln dealership where the lifetime engine cycles of the vehicle will be determined. If a vehicle does not meet a threshold for lifetime engine cycles, the dealership will conduct a high RPM engine cycle accumulation procedure, which aims to identify if the vehicle is equipped with defective intake valves. Any vehicle that fails the accumulation procedure will receive an engine replacement under the recall. In addition to recall 24V635, Ford has stated that it will launch customer satisfaction campaign 24N12, which will provide extended warranty coverage to the subject vehicles through the earlier of 10 years or 150,000 miles. In view of the recall action being taken by Ford, ODI is closing this Engineering Analysis. To review the reports cited in the Closing Resume ODI Report Identification Number document, go to NHTSA.gov.

The contact owns a 2021 Lincoln Nautilus. The contact stated that while the vehicle was at the dealer for an oil change and trade-in, the contact was informed that the front driver’s side door had a crack and that the welding was cracked and loosened. The vehicle was not repaired. The manufacturer was made aware of the failure, and a case was filed. The failure mileage was approximately 92,800.

NHTSA ID

11754393

Incident

Jul 11, 2026

Mileage

92,800 mi

The transmission occasionally jerks/studders between second and third at acceleration and deceleration.

NHTSA ID

11748565

Incident

Jul 5, 2026

2021 Lincoln Nautilus Reserve 2.7-liter twin-turbocharged V6 with coolant intrusion caused by a blown head gasket on cylinder #6. Vehicle would not accelerate properly and lurch forward when the gas pedal was pressed over 25%. The issue was taken to the shop and not found. The issue progressed and was taken to the shop a second time. The issue was found from a misfire code on cylinder #6. Vehicle is currently being repaired.

NHTSA ID

11741378

Incident

May 13, 2026

Vehicle died in parking lot. The electronics all worked, it just would not start and would not go into any gear. Had to have it towed to dealer for repair. They replaced the PCM but it still would not start. They again replaced the PCM and a fuse. The vehicle started. This is the FOURTH time for the exact same issue. It died twice on the previous owner, once while on the highway. It also died twice for the mechanic while trying to diagnose / test drive the unit for the previous owner. We were lucky it died where it could be towed as it's an all wheel drive unit. It has also had an O2 sensor replaced, and the previous owner suffered wiring issues (replaced the engine bay body harness), sunshade recoil failed, abnormal noise in rear end when turning, etc. All issues were corrected. However, I am uncomfortable that these issues may re-occur. Another failure of the PCM and/or electrical issue could cause the unit to die in a situation that could be life threatening.

NHTSA ID

11733835

Incident

Apr 18, 2026

While driving on the highway my transmission died. Had it towed to a nearby forwad dealershiop, Owens Ford in Jarrett VA and they confirmed the transmission died at 51,600 miles.

NHTSA ID

11714494

Incident

Jan 22, 2026

The contact owns a 2021 Lincoln Nautilus. The contact stated that while opening the front driver’s door, there was a cracking sound coming from the door. While the vehicle was in for routine maintenance, the mechanic discovered that the front driver’s side door check arm stop bracket and door hinge were faulty. The vehicle was taken to the local dealer, who examined the vehicle and informed the contact that the front driver’s side door needed to be replaced. The vehicle was not yet repaired. The manufacturer was notified of the failure. The contact stated that the vehicle was previously repaired for the same failure. The failure mileage was 74,000.

NHTSA ID

11712734

Incident

Dec 26, 2025

Mileage

74,000 mi

Door check and spot welds are broken. The car has less the 20,000 miles on it. I was told by the mechanic that he saw this issue with Ford Escapes, there was a recall on the drive side door for the welds failing.

NHTSA ID

11708212

Incident

Dec 2, 2025

The contact owns a 2021 Lincoln Nautilus. The contact stated that while shifted to reverse(R) and depressing the accelerator pedal, the vehicle hesitated and then suddenly jerked backwards. The contact stated that the vehicle almost jumped into gear. The contact stated that later while driving and attempting to accelerate, the accelerator pedal was depressed and the vehicle hesitated and then jolted forward. The vehicle accelerated to approximately 60 MPH. The contact depressed the brake pedal, and the vehicle was jerking while attempting to slow down. The contact was able to stop the vehicle at a traffic light. The contact stated that the "WRENCH" symbol was displayed on the instrument cluster. The contact drove the vehicle back to the residence and then the vehicle was towed to an independent mechanic to be diagnosed. The mechanic had not diagnosed the vehicle but advised the contact that it was possibly a transmission failure and referred the contact to the dealer for assistance. The vehicle was towed to the local dealer. The dealer diagnosed the vehicle and determined that the transmission needed to be replaced. The vehicle was not repaired. The manufacturer was informed of the failure and advised the contact that there were no recalls associated with the VIN for the transmission. The failure mileage was approximately 101,000.

NHTSA ID

11689898

Incident

Jun 4, 2025

Mileage

101,000 mi

This bulletin supersedes 26-2171. Reasons for update: update the Parts list to add a note to clarify the application of the part numbers W520102-S442 and 4S4Z-3N324-AA "FWD Only". Some of the vehicles listed in the Model statement above may exhibit all of the following conditions:  Shudder condition, most noticeable at speeds below 60 mph (100 km/h)  No relevant diagnostic trouble codes (DTC) present  Traceable shudder event with IDS/FDRS reading *(Figure 1)* This condition may be perceived/felt as an engine misfire. This may be due to a concern with the output planetary assembly.

Some 2021-2026 Ford/Lincoln vehicles may exhibit various symptoms including but not limited to the auto start/stop system not operating as intended with a "Check Charging System" message in the instrument panel cluster (IPC) while the charging system is operating properly with no charging related diagnostic trouble codes (DTC) stored. This may be due to someone using an aftermarket programmer to change the body control module (BCM) configuration to disable the auto start/stop system or perform other unsupported programming modifications. To correct this condition on F-150 and Bronco vehicles, download and run the Ford Diagnosis and Repair System (FDRS) application titled "BCM-Charging System Configuration Correction". Running this application will determine if the BCM configuration was modified by the customer and if so, provide the option to return the configuration back to factory settings. For other vehicle models exhibiting concerns related to unsupported aftermarket BCM programming, submit a Technical Support Request (TSR) requesting support to revert the BCM configuration

This bulletin supersedes 26-2194. Reason for update: update the Parts list to correct a part description " Loctite 638", update the claim quantity for the drain/fill plug, update the claim quantity of the wheel hub bolts (Corsair) and limited the parts list for Edge/Nautilus to only the rear drive unit fluid. Some of the vehicles listed in the Model statement above may exhibit all of the following conditions:  Shudder chatter condition, most noticeable at low speeds turning  No relevant diagnostic trouble codes (DTCs) present This may be due to internal rear drive unit (RDU) fluid contamination.

Quality improvements include: - Enhanced system performance, disk usage limits and memory monitoring

Some of the vehicles listed in the model statement above equipped with SYNC4 may experience a blank center display screen or black center display after welcome animation. The rear-view camera will still function when shifting the vehicle to reverse under these conditions.

This bulletin supersedes 25-2627. Reason for update: To add a Step to reprogram the all-wheel drive (AWD) module for Bronco Sport vehicles. Some of the vehicles listed in the Model statement above may exhibit all of the following conditions:  Shudder chatter condition, most noticeable at low speeds turning  No relevant diagnostic trouble codes (DTCs) present This may be due to internal rear drive unit (RDU) fluid contamination.