What 184 owners told NHTSA about the 2018 Ford Mustang

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.

NHTSA ODI 11738968

A check engine light turned on and the vehicle was taken to a local dealership. The check engine light was for an engine misfire and was diagnosed further. There was an engine failure due to coolant entering the system. Upon further research, I learned this is a common issue for 2016-2020 Ford Mustangs and it is due to a faulty engine design. The dealership is recommending a new engine install with a price tag of over 13,000 despite this being known to happen because of a badly designed engine with these cars.

NHTSA ODI 11731787

The vehicle was subjected to the “ecoboom” due to Ford’s lack of care when designing the engine. The car blew the head gasket and now requires an engine rebuild.

NHTSA ODI 11731374

I was told by my mechanic I have a head gasket leak. Turns out there is a class action lawsuit for my 2.3 ecoboost motor for this coolant intrusion problem. It is a known problem. It is a safety issue as I’ve heard of some engine fires. My car only has 56000 miles on it but it is a 2018 so just out of the manufacturer warranty. I’ve reached out to Ford but no definitive answer on whether they will help or not they want me to pay them to diagnose it even though I’ve already had it properly diagnosed

NHTSA ODI 11730972

When driving the car, the engine temperature light came on, pulled the car over to let it cool down, when cooled, drove home and looked in the engine compartment, found the coolant reservoir empty, filled it with proper coolant, next day the engine light came on, took to O'Reilly auto parts to scan code, problem was Cylinder #3 misfire, changed out spark plug, noticed that coolant reservoir was low again, searched internet for possible causes when found that many people are having the same issue, turns out Ford manufactured the 2.3L engines with a faulty design where the cooling leaks into the cylinders "Coolant intrusion". the fix that Ford has established for this issue is to replace the engine with a "long block" version, but will not issue a recall. We have contacted Ford and explained the issue, but they will not repair. This should not be happening to a car with only 27,000 miles. now we are stuck with a car we can't drive and don't have the extra $5,000 plus dollars to replace the engine!

NHTSA ODI 11725806

Engine stopped working while traveling down a major interstate. Upon further inspection, the engine (EcoBoost) was defective and had to be replaced at my expense. This type of engine is known to have a manufacturing defect and was barely out of warranty. Ford would not replace the engine. Thank you

NHTSA ODI 11713953

Random/multiple misfires and cyl 3 misfire (P0300 and P0303). Mechanic used a borescope and found coolant on the walls; visible coolant intrusion in cylinder 3. Coolant has gotten to low levels. Very rough cold start. Mechanic highly recommends to get the engine replaced.

NHTSA ODI 11710053

My 2018 Ford Mustang EcoBoost experienced sudden engine failure at 70,915 miles. The dealership documented misfire codes P0300, P0301, and P0316, which match the known 2.3L EcoBoost coolant-intrusion defect. This defect causes loss of power, rough operation, misfires, and potential stalling, creating a safety risk during driving. Ford Customer Relationship Center instructed me that the dealership must escalate the defect to the Regional Field Service Engineer. However, the dealer refused to do so, leaving the failure unresolved. This appears to be part of a widespread safety-related defect involving 2.3L EcoBoost engines, with risk of sudden loss of power, stalling, and internal engine failure

NHTSA ODI 11701911

There is a coolant intrusion on my vehicle, which resulted in either cracking the engine block or head gasket. In turn, this has caused a costly repair on a car with only 56,000 miles on it. Ford is aware of the issues with these engines and the seals on them. It’s a 2018 Ecoboost! It also happened to my mom’s Ecoboost around the same mileage. This isn’t normal and Ford is literally turning a blind eye to a very serious issue which results in total engine failure. On top of that the repair for this issue is costing $12,000 to repair at the dealership. This is absolutely absurd for a company as big as Ford, to build a faulty engine and then not offer any support/recalls to help all of those affected by it, including me.

NHTSA ODI 11691085

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.

NHTSA ODI 11685148

For roughly 4mths beginning in April 2025, my 2018 Ford Mustang Ecoboost has been suffering from a sporadic misfire, with it the system reporting the misfire and the check engine light coming on, the Ford App identifying the misfire occurring. It was initially repaired with replacing all spark plugs, ignition leads. The sporadic misfire would continue to occur, Ford dealership kept the car for 2 days in late July, took everything apart said they were unable to replicate the misfire, cleared the codes (P0303 being the main one that appears consistently) and said to come back if it occurred again. Roughly 2 weeks later the issue occurred again, took the vehicle back to Ford where they kept the car for 2 days, went through the same process and could not replicate the issue. They dug deeper into the issue and found that the coolant would not hold pressure and with the use of a video scope found that the Intake Valve had fractured and was leaking coolant into the engine as well as distributing multiple shards and pieces of metal from the Valve Intake Fracture. Informed me that the only option was to replace with a new engine and turboboost. They reviewed and found that there were no recalls related to this issue for this vehicle. After undertaking my own research, I found this to be a known issue for Ford and that roughly 100k vehicles had been recalled starting with the 2020 vehicles for the same issue. The out of pocket expense is around 14k, and the vehicle is currently waiting on a replacement engine to arrive. Currently Ford are not offering any assistance in the cost of the replacement, been though they have been servicing the car since 2020 and it is regularly maintained per their guidelines of vehicle needs based on the mileage driven.

NHTSA ODI 11682090

My car engine made a huge boom at only 40,000 miles while on the interstate and I lost all power and almost got ran over by other vehicle because of this. The engine had blown up under normal driving conditions

NHTSA ODI 11681922

The contact owns a 2018 Ford Mustang. The contact stated while driving at an undisclosed speed, the engine seized. There was no warning light illuminated. The vehicle was pushed to a nearby independent mechanic however, the vehicle was not diagnosed. The vehicle was then towed to another independent mechanic where it was diagnosed with a ruptured cylinder #1, causing engine failure. The contact was informed that the engine needed to be repaired or replaced. The vehicle was repaired. The manufacturer was made aware of the failure but provided no assistance. The failure mileage was approximately 18,000.

NHTSA ODI 11673497

I own a 2018 Ford Mustang EcoBoost with a Gasoline Direct Injection (GDI) engine. At around 100,000 miles, the engine developed severe carbon buildup, resulting in cylinder scoring and catastrophic engine failure. Despite following Ford’s recommended maintenance schedule (including a 100,000-mile GDI cleaning service performed by the dealership), my car now has one cylinder with only 70 psi compression (confirmed by borescope and mechanical test). Other cylinders measure 135–160 psi. I have learned Ford is aware of this issue and has made design changes in later models (adding extra fuel pumps/dual injection systems) to address it, but no recall or owner warning has been issued for earlier EcoBoost Mustangs. My research and discussions with BG Products and independent experts show this is a common flaw with GDI-only systems, and Ford has failed to inform owners or provide a lasting solution. The dealership and Ford have offered limited goodwill, but the engine is beyond repair and requires a full replacement. I believe Ford’s failure to warn owners about this well-known defect constitutes a safety and reliability risk. I am requesting NHTSA to investigate this widespread issue and require Ford to take responsibility for affected vehicles.

NHTSA ODI 11670898

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.

NHTSA ODI 11665795

The contact owns a 2018 Ford Mustang. The contact stated that while starting the vehicle, there was a misfire coming from the engine. The contact stated that the vehicle was shaking abnormally, with the check engine warning light illuminated. The vehicle was taken to an independent mechanic, where it was diagnosed and determined that the head gasket had failed, and the engine needed to be replaced. The vehicle was not repaired. The dealer was contacted. The vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 66,637.

NHTSA ODI 11665107

Took Mustang Ecoboost to Ford dealership as result of steady check engine light. Prior to check engine light rough idle at start up that smooths out after 10 to 15 seconds. Dealer identified CYL 3 misfire as well as random misfires. They also observed carbon tracking on plugs. Dealer replaced plugs and performed GDI cleaning service. About three weeks following repair same conditions reappeared rough idle and check engine light. Upon dealer inspection and use of bore scope discovered coolant intrusion in cylinder and recommended long block engine replacement. The second dealer appointment was several days after my warranty expired and mileage was 30,106 miles. Although the dealership was very supportive and understanding Ford would not provide any assistance even after I also pursued relief directly. As a result the long block engine replacement cost is $8,200. After considerable research was able to identify that ecoboost 2.3 engines as well as other small ecoboost engines all had a block defect that has since been corrected. The defect tends to permit, over time, coolant to leak into cylinders. Although a new head gasket may correct the condition, Ford normally recommends long block engine replacement as a long term fix. This condition if not attended to or if coming on suddenly will cause total engine failure. And, as failure can only occur when operating an engine failure under any driving condition is fraught with danger. To my knowledge Ford has not taken any steps to address this issue with the 2.3 liter engine built prior to about February 2020. And, at that time made an engineering change to the engine block addressing the design defect. Additionally, Ford did provide relief to owners of other smaller ecoboost engines having a similar design defect. At the present time there are several class actions suits pending for this 2.3 coolant intrusion issue. One final point should an ecoboost experience CYL or random misfires ensure bore scope is employed.

NHTSA ODI 11661473

The contact owns a 2018 Ford Mustang. The contact stated while the vehicle was stationary, the contact attempted to warm up the vehicle; however, when the contact returned to the vehicle, the vehicle was off. The contact attempted to restart the vehicle and the check engine warning light illuminated. The contact restarted the vehicle however, the engine sounded like it was losing power with an abnormal ticking sound coming from the engine. The message to “Shift to Park” was displayed; however, the gear shifter was already in park(P). The vehicle was towed to an independent mechanic, the vehicle was diagnosed with engine failure due to a lack of engine oil. The vehicle was not repaired. The dealer was not made aware of the failure. The manufacturer was not made aware of the failure. The failure mileage was approximately 129,000.

NHTSA ODI 11655943

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.

NHTSA ODI 11653988

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.

NHTSA ODI 11649393

Engine block failure at 47k miles. Car was driven at 1/4 throttle or less when detonation occurred creating a hole in the engine block. This is so prevalent that it is colloquially termed “ecoboom.” Cost of repair is nearly $9,500

NHTSA ODI 11634329

For three years, this Mustang will lurch frequently after you shift into first or reverse from park. I had it looked at Paradise Ford 3 years ago and they REFUSED to look at transmission until the car had 125k miles on it. At that time, the car only had 98k miles on it. I tried to insist, but they refused. The service helper was named Mark, I believe. The other day I was driving on a 10mph park road .....more like coasting because it was a low speed limit. The car suddenly jerked forward. Today I took it into Gary Yeoman Ford in Palm Bay, FL for a transmission check. The service advisor was Jason. They said there was a cdf hub issue and stated I needed a new transmission for 6600.00. Of course I refused and came home to research their "diagnosis". I found an article about a,10R80 bushing that has caused the same exact problem is other Mustangs. I feel like they were giving me the run around. I don't want this to cause further problems. It should have been fixed at Paradise Ford. I have owned this car for 5.5 years. I'm quite familiar with how it runs. Please advise.

NHTSA ODI 11633728

Due to a faulty design were antifreeze is allowed to get into the cylinders and mix with the oil, the engine malfunctioned while I was on a busy highway and I barely got off the road onto the shoulder. It was very dangerous. I thought it was an isolated incident but it happened again. Now they want to charge me $8,400 to replace a defective engine. I know some of Ford's similar engines are being recalled. Thank you

NHTSA ODI 11616290

We purchased this vehicle for my daughter as a graduation present and while she was driving it the engine malfunctioned stranding her on a busy highway. We then found out it is the defective EcoBoost engine manufactured by Ford that was the cause of this incident. We have been trying to get it repaired but Ford will not cooperate even though they know this engine is a defective product. Could we please get some assistance with this as we just purchased this vehicle a year ago and we are now being asked to spend $8,000 to replace a defective engine. Thank you, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6) INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11595235

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.

NHTSA ODI 11589695