2020 Ford Mustang

Vehicle has 396 miles on the odometer. While preparing to back up, with the engine idling , the engine shut off without warning and I had no control of the steering and would not restart when I attempted to do so. This could have put anyone behind me at sever risk or maybe caused an accident should I have been on the highway. The car was towed to my Ford Dealer (Varsity Ford, Ann Arbor, MI) and after inspection they informed the engine had a failure and needed to be replaced and gave me a price of $19,900. No other warning lights or messages prior to complete engine failure.

2020 Ford Mustang with the 2.3L EcoBoost engine. The vehicle has a documented history of coolant loss with no visible external leak, consistent with the known coolant-intrusion defect in Ford's 2.3L EcoBoost engines where coolant leaks internally into the cylinders. The vehicle previously threw a cylinder misfire code (P0301) and now shows a crankshaft/camshaft timing correlation fault (P0017). A scan tool confirmed the exhaust camshaft is approximately 18–19 degrees out of correlation. A new variable valve timing oil control solenoid was installed and did NOT resolve the fault, confirming the problem is mechanical — a worn/stretched timing chain. This wear is consistent with the oil dilution and contamination caused by internal coolant intrusion. The problem has been confirmed by an independent service center via scan data. The vehicle is available for inspection. Warning symptoms included the check engine light, a loud rattle on cold startup, and occasional hard/no-start conditions. This is a safety concern because internal coolant loss can cause overheating, cylinder head cracking, and potential engine failure or fire while driving. Repair cost quoted at approximately $2,000. Mileage approximately 54,400.

I own a 2020 Ford Mustang EcoBoost with approximately 75,000 miles. My vehicle developed a check engine light with diagnostic codes P0300 (random misfire) and P0301 (cylinder 1 misfire). I also began experiencing white smoke from the exhaust during cold starts. An independent repair shop suspects coolant is entering cylinder 1 due to a possible head gasket failure. They have recommended removing the cylinder head to inspect for cracks, check for warping, pressure test the head, inspect the cylinder walls, and replace the head gasket and related components if no further engine damage is found. The vehicle was properly maintained, and these symptoms appeared unexpectedly.

Check engine light came on, car lost power on highway. Car continues to have the same issue after repairs have been made. Ford App says engine misfire, after every repair. Ford mechanics fix spark plugs, coils, electrical. None of which has fixed the issue of stalling on the highway which poses risk of me the driver and others driving on the highway. The only light that comes on is engine light.

IMRC actuator rod broke causing the air/fuel mix to be sporadic. Creating a misfire on random cylinders. Major loss of power and very jerky motions, causing the vehicle to loose control. Luckily it was on an open spacious road. Unfortunately this has been an ongoing problem and there is nobody selling updated parts the electronics will recognize and very difficult to find oe replacement parts, real costly. And may fix the issue for a short period of time. I have a brand new manifold off of a same totaled mustang since Dec 2025 and the same part broke.

FAILURE TO NOTIFY/ADDRESS A KNOWN ISSUE DURING THE WARRANTY PERIOD Vehicle has been serviced in accordance with Ford’s recommended maintenance schedule by Joe Cooper Ford of Edmond, Oklahoma, since purchase. At service appointment in September 2025, with 59,968 miles – just prior to the 60k mile powertrain warranty expiration – specifically requested a thorough inspection of any conditions that could potentially be addressed under warranty coverage. During that visit, Joe Cooper Ford documented that the “coolant was low (at minimum mark) and dirty” and recommended a coolant system fluid exchange. This finding occurred in the context of the well-documented coolant intrusion defect affecting 2017–2020 Ford Mustangs and other Ford models. When an authorized dealer observes conditions consistent with a known defect during the warranty period, reasonable warranty administration requires disclosure and further diagnostic evaluation, so the customer has a meaningful opportunity to pursue timely repair. By January 2026, at only 61,640 miles, were informed our engine had failed. No such disclosure or evaluation was provided. As a result, we were deprived of a reasonable opportunity to address the condition under warranty prior to expiration. The subsequent engine failure occurred after the warranty period but was directly preceded by these unresolved indicators. Under these circumstances, denial of warranty consideration is inconsistent with the purpose of the warranty and reasonable consumer expectations.

The vehicle has ongoing engine and turbocharger problems, including loss of power, knocking, and worsening performance. It also has brake‑booster/vacuum issues that cause reduced braking assist and a hard brake pedal. Electrical and software malfunctions occur intermittently, including warning messages and irregular system behavior. These issues create safety risks and have been observed repeatedly. Some problems were confirmed by service technicians, but the exact cause remains unknown.

1. 2020 Mustang Ecoboost is equipped from factory with redesigned block to minimize/eliminate coolant intrusion and or head gasket failure. I still had the dreaded "ecoboom" issue with coolant intrusion on two cylinders as a result of a broken head gasket and poor engine block design. Regular maintenance was perfomed and use primarily Top Tier 93 octane fuel. 5K mile interval 5W-50 oil changes according to manual using Ford spec oil full synthetic. Cold Start Misfires and excessive engine shaking are still occurring despite short block replacement by Ford and they won't diagnose properly. 2. Electrical/Audio. Issue with crackling audio, audio skipping and both iPhones and Androids having disconnection issues. Factory reset the Sync module twice, attempted reset by unplugging car battery and also checked alternator. Replaced car battery with fresh battery and issue persists. 3. Powertrain: The 10R80 Auto Transmission is extremely jarring and does not shift smoothly. Hesitates throughout gears, sluggish gears changes. Gives whiplash effect even after a filter and oil change for the transmission with OEM fluid and filter. Premature Transmission gasket housing failure as well causing ATF to leak onto ground.