Ford Mustang check engine light comes on

Filed Oct 13, 2026 · Engine, Transmission · NY

The 2.3L EcoBoost engine failed due to coolant leaking into the combustion chambers. The dealer found coolant present in cylinders 1 and 4, the cylinder 4 piston washed, and vertical scoring on the cylinder 4 wall. The dealer's recommendation is complete engine replacement. Yes, the engine is available for inspection. The vehicle is currently at the Ford dealership and the engine has not yet been replaced. Coolant entering the cylinders causes misfiring and loss of engine power. The vehicle shook on startup and ran roughly, and the misfire was intermittent and unpredictable. A sudden loss of motive power while driving in traffic or at highway speed is a crash risk to me and to other drivers. Coolant loss into the cylinders also reduces the coolant available to cool the engine, creating a risk of overheating. The vehicle is currently not safe to drive. A Ford dealership has reproduced the issue and confirmed it. The technician retrieved stored codes P0304 and P0316, removed the spark plugs and coils, and borescoped the cylinders. A cooling system pressure test was performed and the vehicle was allowed to sit, after which borescope inspection confirmed coolant in cylinders 1 and 4. This was the second visit for the same concern. At the first visit, in August 2026, the dealer replaced all four spark plugs and the cylinder 4 ignition coil, and the misfire returned within weeks. The vehicle has been inspected by an authorized Ford dealership. A goodwill assistance case has been opened with Ford Motor Company and Ford has offered partial coverage of the repair. No police or insurance inspection has occurred. The check engine light illuminated and the vehicle shook on startup and ran roughly. These symptoms first appeared in August 2026 at approximately 32,600 miles. The dealer replaced spark plugs and an ignition coil at that time and the symptoms returned within weeks. Check engine light was not illuminated at the second visit, but codes were stored in memory.

Filed Oct 2, 2026 · Engine · AL

Check engine light came on Sunday night. Monday had AutoZone check the codes - indicated misfire on two cylinders recommended spark plug replacement - Spark plugs purchased with intent to change Tuesday evening- Tuesday morning -Engine overheated on the way to class added more coolant - got the vehicle home and towed to local Ford Dealership the next day to learn that the coolant was leaking into the engine due to head gasket failure. Ford said the engine needed to be replaced.

Filed Sep 29, 2026 · Acceleration, Steering · MD · crash · 1 injury

Vehicle Information: 2022 Ford Mustang Date of Incident: XXX Description of Safety Defect & Crash: On XXX, this vehicle suffered a catastrophic concurrent failure of the electronic throttle control and steering systems, resulting in a violent injury crash. Prior to the incident, the vehicle was completely disabled due to electronic throttle errors, requiring us to rent a U-Haul tow dolly to physically haul the vehicle to Apple Ford in [XXX]. The dealership replaced the throttle body assembly to address a wrench/check engine light and airflow codes (DTC P050A). Exactly 30 minutes after picking up the vehicle from the dealership, while driving home at normal speed limits, the vehicle suffered a sudden, uncommanded wide-open throttle failure. The RPMs violently spiked and the supercharger engaged aggressively without driver input. Simultaneously, the steering wheel suddenly and aggressively forced itself completely to the right. The steering wheel violently locked in the rightward position; the driver actively attempted to pull the steering wheel back left, but the vehicle overrode his physical inputs completely. Because the electronic throttle and steering systems completely overrode driver control, the vehicle broke traction from the rear and veered sharply off the roadway, striking a tree. The uncommanded engine force was so severe at impact that the vehicle was launched into the air and rolled until stopped by a second tree. The driver sustained a broken fingertip and severe body bruising, requiring emergency hospital evaluation. Certified phone logs confirm the driver was on a hands-free call troubleshooting the initial mechanical instability up until the exact minute (12:19 PM) the final catastrophic failure occurred and a 911 emergency call was placed. The vehicle is currently being transferred to a Progressive Insurance facility for total loss processing. We are requesting a federal review . INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Sep 29, 2026 · Electrical · 21,000 miles · FL

The contact owns a 2025 Ford Mustang. While the contact’s daughter was driving 20 MPH, the vehicle lost automotive power. The check engine warning light was intermittently illuminated. The vehicle was pulled over to the side of the road and was restarted to continue driving. The vehicle was taken to a dealer to be diagnosed, and the contact was informed that the failure was not duplicated. The manufacturer was notified of the failure. The contact associated the failure with the federal safety agency Campaign Number: 26V547000 (ELECTRICAL SYSTEM). The failure mileage was 21,000.

Filed Sep 24, 2026 · Driver assistance, Electrical · TX

The electrical components in the vehicle stopped functioning - for the lights on the interior the overhead stopped working on and off and then dimmed until one day never came back on. At the same time the sensor for cross traffic alert became buggy and then not functional which made all my safety features and cruise control not work. Now I have a TPMS sensor and check engine light with nothing serious wrong

Filed Sep 22, 2026 · Engine · FL

Engine coolant leaked into the cylinders. Overheating. Coolant leaked into catalyst. ODB Error codes attached . Independent service center replaced short block, see attached invoice. Engine light on.

Filed Sep 17, 2026 · Fuel system · FL

On or about June 24, 2026, the CHECK ENGINE light came on. Since I was near the local Ford Dealership, I stopped there. The car was evaluated the next day. I was told the the gas tank assembly and pipe had to be replaced. The repair was almost $4000. My car only as 63,117 miles on it. Before the problem was diagnosed, I was getting lousy gas mileage and assumed it was because the government was allowing more ethanol. In fact, the problem could have been disastrous... The car could have caught on fire . The car was in the repair shop until July 2, and I had to rent a car for $300. I am unable to download a photo I have of the gas tank which shows these numbers: E-11 34RI-020135 as well as AD46319. I have attached the bills from the CERTIFIED FORD repair shop. Please note that the 2015 Mustangs were recalled for gas tank replacements. I have a 2016.... Seems like my car may have had a faulty gas tank installed as well. The mechanic said he had replaced a couple. Nite that the car had just over 63000 miles

Filed Sep 17, 2026 · Electrical · 27,500 miles · FL

The contact owns a 2024 Ford Mustang. The contact stated that while driving 75 MPH, the vehicle stalled. The contact coasted the vehicle to the side of the road, shifted to park(P) and waited five minutes, and restarted the vehicle. The failure was a recurring failure. Additionally, the vehicle lost windshield washer fluid pump functionality and days later by the check engine warning light illuminated due to a weak or failing battery. The contact associated the failure with the federal safety agency Campaign Number: 26V547000 (Electrical System). The dealer was contacted but was unable to reproduce failure and stated that vehicle needed a software update. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The failure mileage was approximately 27,500.

Filed Sep 11, 2026 · Engine, Fuel system · TX

I own a 2018 Ford Mustang EcoBoost Premium with the 2.3L EcoBoost engine. The vehicle initially developed a check-engine light and was diagnosed with P0303 (Cylinder 3 misfire), P0316 (startup misfire), and P018C (fuel pressure sensor circuit low). On August 24, 2026, all four spark plugs and one ignition coil were replaced, and a fuel/induction cleaning service was performed. The P018C repair was declined at that time. On September 10, 2026, the vehicle started with an extremely rough idle and produced a very large cloud of white, sweet-smelling exhaust smoke. The check-engine light came on. The original codes, including the misfire codes, were present along with additional codes. The vehicle underwent approximately three hours of diagnostics and road testing. The codes were cleared, and afterward only P018C returned. Testing reportedly did not identify a head-gasket leak, but visible white smoke was still coming from the exhaust when I left the repair facility. Possible coolant intrusion involving the turbocharger was discussed, but the source was not confirmed. Later that day, the vehicle would not crank in Park but started in Neutral. While driving home, the engine began idling so violently at a traffic light that the entire vehicle shook and the tachometer fluctuated significantly. Before September 10, the vehicle had never produced white exhaust smoke, never shaken violently at idle, and always started. The repair facility attempted to inspect the cylinders with a borescope, but both of its borescopes were not functioning. I am concerned about possible coolant intrusion or another engine defect because of the Cylinder 3/startup misfire history, heavy white sweet-smelling exhaust, and severe intermittent rough running. The cause has not yet been confirmed, and I am concerned about possible engine failure or loss of power while driving.

Filed Sep 11, 2026 · Engine · TX

I own a 2018 Ford Mustang EcoBoost Premium with the 2.3L EcoBoost engine. The vehicle initially developed a check-engine light and was diagnosed with P0303 (Cylinder 3 misfire), P0316 (startup misfire), and P018C. On August 24, 2026, all four spark plugs and one ignition coil were replaced and a fuel/induction cleaning was performed. On September 10, the vehicle suddenly started with an extremely rough idle and produced a large cloud of white, sweet-smelling exhaust smoke. The check-engine light illuminated and the previous codes returned along with additional codes. The vehicle continued producing white exhaust smoke after several hours of diagnostic testing. Later that day, the engine shook violently while I was stopped at a traffic light and the tachometer fluctuated significantly. On September 11, the check-engine light returned and the previous diagnostic codes were again present. Firestone documented that coolant was present in the exhaust, that the coolant level was low again after coolant had been added the previous day, that the engine was burning coolant and producing white smoke, and that coolant was mixed with the engine oil. Firestone stated the engine may have a cracked head, failed head gasket, or internal engine crack and recommended complete engine replacement. The engine has now suffered a serious internal failure severe enough that the repair facility recommends replacement. The vehicle has exhibited violent shaking, unstable engine speed, repeated misfires, rapid coolant loss, coolant contamination of the engine oil, and coolant burning through the exhaust. I am concerned that continued operation could result in complete engine failure or sudden loss of engine power while driving, creating a significant safety hazard in traffic. Before September 10, the vehicle had never produced white exhaust smoke or experienced this severe shaking. I am reporting this as a potential safety defect involving the 2.3L EcoBoost engine.