2019 Ford Mustang

Coolant intrusion into cylinder 2 at 26,000 miles. Was told by mechanic this is due to thin cylinder wall design between cylinder 2 and 3. And the thin coolant channel cut between them. A new engine block manufactured after 2020 was recommended because the engine design was changed to fix this issue. My warranty expired 4 months prior so I had to fix myself.

The contact owns a 2019 Ford Mustang. The contact stated that while driving approximately 85 MPH, the passenger’s side door ajar warning light illuminated, and the contact heard an audible chime. The contact stopped the vehicle and pushed on the door from inside the vehicle, and the door opened without using the door handle. The contact stated that failure had occurred three times. The contact became aware that the failure occurred after driving over a bump or pothole in the road. The contact stated that the power door locks were functioning with the key fob and while using the interior door lock button. The vehicle was taken to a local dealer, and the contact was informed that there was no recall or TSB related to the failure. The vehicle was not repaired. The manufacturer was informed of the failure. The failure mileage was approximately 69,000.

On Repair Order #:[XXX] at Lorenzo Ford, the dealership technician documented the following: “Verified customer concern, DTC P0304 perform pinpoint test, inconclusive, perform coolant pressure test and found coolant intrusion into cylinder 4.” This confirms a coolant intrusion defect causing misfire and overheating — exactly the well-documented issue affecting 2.3L EcoBoost engines that is now the subject of a pending class action lawsuit (filed June 2025). INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

I purchased this 2019 Ford Mustang Ecoboost 2.3L brand new in July 2019. It has been well maintained, regularly serviced by the authorized Ford Dealer where I purchase the car. It has never been in an accident, and has only 36,100 miles. This vehicle passed inspection last month. The check engine light came on, and then had rough cold starts. I have been informed by the service station that antifreeze is leaking into the engine, and a new engine is required (estimated cost of $11,000). After researching this matter, it appears that there is a design flaw with this vehicle, given the high number of similar occurrences with 2015-2019 Ford ecoboost vehicles. It is my understanding there is even a class action lawsuit related to this issue. Luckily, there was no accident resultant from this engine malfunction in my case, but the NHTSA should investigate this issue, given the high risk it poses to highway safety!

My vehicle experienced a blown head gasket due to a faulty engine block design at 56K miles. The car started running rough for 10 seconds upon a cold start up and was also misfiring. This is due to coolant intrusion through the gasket and it got into cylinder 3 which could have caused catastrophic engine failure or worse.There are several class-action lawsuits against Ford for the defect.Ford has not taken any steps to address this issue with the ecoboost engines on 2015-2019 models. Additionally, Ford did NOT provide relief to me and I had to pay out of pocket to fix this.

My door pops open while driving. You can hear it and the dash lights up that the door is ajar. Have to pull over and open and close the door. This has happened multiple times during various speeds and road conditions. Ford has recalled the door latches on the years prior but this year is not included. It has been occurring for over a year about 3 times a month.