2018 Ford Mustang: engine overheating

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 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.

Filed May 20, 2026 · Engine · GA

1. Component failed and availability for inspection: The engine assembly block failed due to a manufacturing defect known as "coolant intrusion into the cylinders." The vehicle and the defective engine are currently located at my residence and remain fully available for federal or manufacturer inspection upon request. 2. Safety risk: The safety of myself and others was severely compromised. Coolant entering the combustion chambers causes sudden, severe engine misfires across all cylinders, erratic power loss, and instantaneous stalling. Operating a vehicle where the engine can suddenly lose all power on high-speed roads creates an immediate risk of rear-end collisions and catastrophic traffic accidents. Furthermore, high-pressure internal coolant leaks pose an inherent risk of engine fires. 3. Problem confirmed by a dealer: Yes. The problem has been officially diagnosed and confirmed by an authorized Ford dealership service center, which documented internal coolant intrusion. 4. Inspected by manufacturer, police, or insurance: The component was inspected and verified by the vehicle manufacturer's authorized dealership technicians. It has not been inspected by the police or insurance representatives, as no crash has occurred yet. 5. Warning lamps, messages, or symptoms prior to failure: Prior to the diagnosis, the vehicle exhibited a "Check Engine Light." Currently, the vehicle is suffering from critical failure symptoms: the Check Engine Light is flashing constantly, the engine misfire codes are actively showing on all 4 cylinders, and the vehicle shakes violently at low RPMs (rough idling). These severe symptoms first appeared approximately 2 moths ago and have progressively worsened due to the coolant intrusion.

Filed Sep 4, 2025 · Engine · AR

My engine began experiencing misfires at around 40,000 miles. They were on and off. The check engine light would pop up and go away for around a month. Then the vehicle began having a rough start and check engine light would not go away. I sent the vehicle back to the dealer where they determined that my engine was having misfires due to a coolant leak into cylinder one, stemming from a poor engine design. The engine needed to be replaced. The repair was covered under my warranty.

Filed Jun 9, 2025 · Engine · FL

Check engine light came on. Took car to dealership where I learned that the car needs a new engine due to coolant leaking into the cylinders. I later learned this is a "known issue" with this engine, yet Ford has refused to fix or do a recall. The engine could fail or catch on fire if not replaced.

Filed Apr 25, 2025 · Engine · 49,000 miles · MA

The contact owns a 2018 Ford Mustang. The contact stated that the check engine warning light was illuminated. The vehicle was taken to a certified mechanic who diagnosed the vehicle with a misfire in cylinder #1, and coolant leaking into the engine. The mechanic referred the contact to the dealer. The vehicle was taken to the dealer who confirmed the diagnosis and that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and opened a case. The manufacturer referred the contact to the federal safety agency Hotline to report the failure. The failure mileage was 49,000.

Filed Apr 10, 2025 · Engine · TX

Head gasket failure from research online there seems to be a flaw in the engine block that leads to coolant leaking in between cylinder walls causing premature head gasket failure.

Filed Mar 20, 2025 · Engine · FL

Ford selling vehicles with malfunctioning engines. This malfunction is allowing coolant to mix in with the oil causing misfires, which leads to the car consuming all of its coolant which can cause the engine to catch on fire. Ford has known about this issue for years and are not trying to put a recall on the engine. They’re making customers pay out of pocket to fix the engine. the dealer determined that the failure was a result of coolant intrusion into cylinder #2 #3. Due to the failure, the engine needed to be replaced. There’s been reports of the vehicle engine completely shutting down while people are driving on the roads. There’s been reporting of the car overheating and catching on fire. The vast majority of consumers who bought the 2.3 liter engines from years 2013-2019 are experiencing these problems. While driving on the highway, the vehicles engine misfired causing lost of power. Luckily I was able to move to the side.

Filed May 20, 2024 · Engine · MD

Ford Incorporation is selling vehicles with malfunctioning engines. Ford cut in between each cylinder block to allow the coolant to cool the engine, however this design is extremely flawed, it causes the head gasket seal to break. This malfunction is allowing coolant to mix in with the oil causing misfires, which leads to the car consuming all of its coolant which can cause the engine to catch on fire. Ford has known about this issue for years and are not trying to put a recall on the engine. They’re making customers pay out of pocket to fix the engine. Replacing the head gasket isn’t an enough to fix the problem because the oil and coolant are mixing inside of the engine. There’s been reports of the vehicle engine completely shutting down while people are driving on the roads. There’s been reporting of the car overheating and catching on fire. The vast majority of consumers who bought the 2.3 liter engines from years 2013-2019 are experiencing these problems.

Filed Apr 25, 2024 · Engine · 58,000 miles · FL

The contact owns a 2018 Ford Mustang. The contact stated while driving at an undisclosed speed, the engine over heated. The engine overheated warning light was illuminated. Additionally, the engine was misfiring. The vehicle was towed to the residence. The vehicle was then towed to the dealer where it was diagnosed with a failed engine due to coolant leak into the engine. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 58,000.

Filed Sep 15, 2023 · Engine · 23,000 miles · CA

The contact owns a 2018 Ford Mustang. The contact stated while driving approximately 15 MPH, the overheated engine message was displayed. The vehicle was taken to the dealer to be diagnosed. The contact was notified of coolant intrusion into cylinder #1. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and informed the contact that the engine in the vehicle was no longer being produced. The approximate failure mileage was 23,000.