Table 1 shows one common engine and engine cooling related problems of the 2020 Ford Mustang.
| Problem Category | Number of Problems |
|---|---|
| Engine And Engine Cooling problems |
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.
I had the coolant gasket problem that resulted in having to get the engine replaced. It was a 202 Mustang ecoboost premium.
Coolant intrusion into cylinder/cylinders problem confirmed by a dealer check engine light, cylinder 1 missfire is when I noticed an issue.
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.
2020 and above Mustang ecoboost 2. 3l engines are supposed to have the revised engine block design to mitigate coolant intrusion into cylinders and head gasket leak issues. My 2020 model year Mustang ecoboost with the updated block, is suffering from coolant intrusion into cylinder #1. Confirmed by independent ase certified repair shop as well as Ford dealership. No codes. Symptoms includes cold start misfires and cold start white smoke from exhaust. Mpg was inconsistent as well since the air/fuel ratio is disturbed by coolant intrusion. Car is at roughly 37k miles. If issue is not remedied, your engine may blow up during operation without warning.
The contact owns a 2020 Ford Mustang. The contact stated while driving at an undisclosed speed, there were several unknown warning lights illuminated. Additionally, the contact noticed smoke inside the vehicle and there was smoke coming from under the hood. The vehicle was towed to the dealer where it was diagnosed with failed pistons and a blown 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 and a case was filed. The contact was advised to contact the NHTSA hotline to report the failure. The failure mileage was approximately 73,300.
On 03. 29. 25 (Saturday) the car started rough and the check engine light came on. I took it to the mechanic 03. 31. 25 (Sunday) and they inspected the car and told me that it is either the head gasket or the engine block is cracked because there is coolant intrusion into the cylinders. They asked me to call Ford customer service and ask if there was any way to cover it under warranty as the car only has 64k miles. I was told no, the warranty was 5yrs or 60k whichever came first and the 5 years was October of 2024. They suggested I file a report with the NHTSA. The vehicle right now is at the mechanic as I try to decide what I would like to do with it. If the engine failed when driving, I don't know what would have happened. There were no other symptoms to the problem prior to the failure. In fact, weeks earlier I had it inspected to see if any maintenance was needed and it got a clean bill of health.
The contact owns a 2020 Ford Mustang. The contact stated while driving 55-60 mph, the check engine warning light illuminated. The vehicle was taken to autozone, where the contact was informed that there was no coolant in the vehicle. The contact added coolant to the vehicle; however, the failure persisted. The vehicle was taken to the dealer, where it was diagnosed that the head gasket had failed, causing coolant intrusion into the engine. The dealer determined that the entire long block and the head gasket needed to be replaced. Additionally, the dealer informed the contact that the long block and the head gasket needed to be aligned correctly. The vehicle was not repaired. The manufacturer was notified of the failure and offered to partially cover the cost of the repair. The failure mileage was approximately 53,500.
The contact owns a 2020 Ford Mustang eco boost. The contact stated that while driving at 25 mph, the check engine warning light illuminated. The vehicle overheated while driving. The contact was able to pull over. The vehicle was towed to the local dealer, where it was diagnosed that there was coolant in the combustion chamber, engine block, cylinder head, and low-pressure fuel pump failure. The dealer recommended an engine replacement. The vehicle was not repaired. The vehicle was taken to an independent mechanic who replaced the head gasket, but the failure recurred. The manufacturer was contacted, who referred to the NHTSA hotline. The failure mileage was approximately 86,000.
The contact owns a 2020 Ford Mustang. The contact stated that after adding oil to the engine, the contact became aware that a significant amount of the engine oil had leaked out onto the ground. The vehicle was not diagnosed or repaired by an independent mechanic or a dealer. The manufacturer was notified of the failure and informed the contact that they could not assist because the VIN was not under recall for the failure. The failure mileage was approximately 72,000.
The contact owns a 2020 Ford Mustang. The contact stated that the engine warning light was illuminated. The vehicle was taken to the local dealer, where it was diagnosed and determined that the catalytic convertor and active grill shutter assembly needed to be replaced. The vehicle was not repaired. The manufacturer was contacted and referred to the NHTSA hotline. The failure mileage was approximately 86,000.
The contact owns a 2020 Ford Mustang. The contact stated that the engine overheated while driving at various speeds with the temperature gauge showing that the engine was hot(h). The contact stated that the vehicle hesitated while depressing the accelerator pedal with an engine misfire alert on the Ford app. The vehicle was taken to a dealer where a pressurized test was performed; the test showed no defect with the engine. The contact then took the vehicle to an independent mechanic where the spark plugs, and cabin air filter were replaced, and the fuel system was cleaned. The check engine warning light illuminated soon after the repair. The vehicle was taken back to the dealer where it remained unrepaired. The manufacturer was notified of the failure and a case was filed. The failure mileage was approximately 59,000.
The contact owns a 2020 Ford and stated that while driving at 15 mph the check engine light illuminated and the vehicle lost power. The vehicle was taken to a dealer where it was diagnosed that coolant leaked in the engine, causing misfiring codes and lack of power which resulted in the engine needing to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 66,500.
A 2020 Ford Mustang eco boost premium 2. 3l l4 dohc 16 valve 6-speed manual with push button start convertible top burst into flames on [xxx] at about [xxx]. The entire car and the black box were consumed by flames that spread to my carport, shed and mobile home. From what I read; it might have been designed for a road racing car. I am [xxx] , and requested a small car from enterprise and this is the only car they had for me. Zero to 60 mph: 4. 9–5. 7 sec zero to 100 mph: 13. 5–15. 5 sec standing ¼-mile: 13. 4–14. 3 sec top speed: 145–155 mph. Why would they have put [xxx] in this car? I drove it as cautiously as I drive my 2011 taurus. I did nothing to cause this fire. I have reached out to fmc and enterprise and have finally come to terms that I have to ask for charity to get the home livable. We run a gas generator for one air conditioner, small frig and well pump for water. The roof leaks, the firefighters puled every outlet in the rooms near where the fire entered my home. The electric meter was pulled off my pole as is standard procedure in my county. Now I am begging for a new roof and a new 200 amp box and all new wiring so the county will allow the electric to be connected again. Fmc did not design this car well. It caused a disaster for me and my family. I cannot afford a new home, I just want to get this one livable. Entreprises had rimkus do a complete investigation which revealed nothing. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).
The contact owns a 2020 Ford Mustang. The contact stated that while driving at 15 mph, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. The check engine warning light illuminated, and the vehicle was misfiring. Additionally, the vehicle was shaking, and the contact pulled over to the shoulder of the road. The contact turned the vehicle off and restarted the vehicle. The vehicle was driven to the residence. The contact stated that the failure was persistent. The vehicle was taken to the dealer where it was diagnosed with coolant leak into the cylinders and the engine needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and advised the contact to report the failure to the NHTSA hotline. The failure mileage was approximately 63,000.
I hope this letter finds you well. I am writing to bring to your attention some serious safety issues that I have encountered with a 2020 Mustang that I purchased from carmax, west valley on September 24, 2023. Soon after taking possession of the vehicle, I noticed a malfunction with the airbag system. It is disheartening to report that I had to endure a three-day wait to have the necessary repairs carried out. The delay in rectifying this crucial safety feature is highly concerning, as it exposes both the driver and passengers to unnecessary risks. Unfortunately, the problems did not end there. Shortly after the airbag issue was addressed, the engine light illuminated on the dashboard. Despite my efforts to troubleshoot the problem myself, the light remained illuminated, indicating a persisting issue with the engine. Not only did this cause me considerable inconvenience, but it also raised concerns about the overall reliability and safety of the vehicle. The most alarming incident occurred on October 2, 2023, when my car unexpectedly broke down while I was driving on the freeway. This unexpected failure not only posed a significant risk to my safety but also left me traumatically shaken by the experience. I cannot emphasize enough the fear and anxiety I felt as I navigated the dangerous situation caused by the vehicle's sudden malfunction. I am deeply disappointed by the lack of quality control and the subsequent safety hazards that have plagued my 2020 Mustang. As a consumer, I have a reasonable expectation that the vehicle I purchase will be safe and reliable. It is distressing to find myself in a situation where my safety and wellbeing are compromised due to these issues. I have taken my concerns up with carmax and I am waiting for a response. It is my hope that they will investigate the matter and take measures to address it. I will not stop fighting for the safety of my family and myself.
Engine tick after first oil change. Transmission shifts hard.
The gas tank was only getting 10 gallons of gas and not 16 gallons like it was suppose to. We ended up running out of gas on a road trip with our two young daughters in the middle of the night on I-75. The gas tank said you had 100 miles to go before empty and then 3 miles later it would drop to 0 and you were running out of gas. This car was used in street racing which was late devulged to us after we found out that at 20,000 miles a whole new engine was put in without our knowledge when we purchased the vehicle . We took it to the dealer and they put a new fuel assembly unit in it. It fixed the problem a little but never fully. Now, 2 days ago my husband with my youngest daughter ran out of gas again on us-19 and I had to leave work to go get them and gas. Next on the 57 things wrong with this car… 5 days after purchase it had 22 engine warning. Took it back and they replaced the 4th coil and the 4th injector and spark plug. About 3 days later my husband came flying into his work, ran by me grabbing a fire extinguisher and ran to the car and started shooting it at the car, the car had caught on fire and the 4th injector was spewing gas. They had pinched an oring while installing the injector and never put the clips back on the injector rail to keep them in place. My husband could have been killed easily. The dealership never took ownership for it and blamed it on the dealership that sold us this the car. Every time we turn around it’s something else. The month of December we only had the car 6 days. It was in the shop 3 different. Times and everytime we got it back it wasn’t fixed. We bought this car in September and it had had 52 engine lights, over 10,000 in parts and labor to fix. Four rentals cars a new battery list goes on. We have tried numerous times to ask the dealership to make this right and their answer is for us to sell them the car back less our 20,000 deposit and buy a whole new car from them. That’s the solution we were given.
This 2020 Mustang gt VIN# 1fa6p8cf0l5171218 with 9,600 miles was a total loss that happened on 10/28/2022 paid out by insurance company usaa 1-800-531-8111. Please take note that this vehicle was a total loss with severe frame damage. My name is ricky thomas and owned the vehicle when it was a total loss due to a meager collision on 10/28/2022. If you have any questions please contact me at 614-725-9945 or rickt625@gmail. Com. I have all of the documents of the total loss and pay out from usaa ins. 1-800-531-8111. Thank you! ricky thomas.
Intermittent loss of throttle with wrench light. Engine goes into derate, have to shut off car, let sit for 3-5 minutes, restart then ok until it occurs again. Loss of throttle at any time is unsafe. Two Ford dealers have tried to repair with no luck. They have replaced the throttle pedal assembly, the throttle body, and now the pcm. Problem is still present. Have an ongoing Ford customer service case #cas44568044-d6g8f8. Still awaiting resolution. Vehicle is still under 3/36 base warranty. Problem has been ongoing for a little over a year now.
The contact owns a 2020 Ford Mustang. The contact stated that while driving at 45 mph, the vehicle was jerking and shaking uncontrollably. There were no warning lights illuminated. The contact was able to continue to drive the vehicle. The contact stated that the failure recurred increasingly while driving on the interstate. The contact veered to the side of the road. The vehicle was towed to the contact’s residence. Then the vehicle was towed to the dealer who diagnosed that no issues were found. The manufacturer was notified of the failure and referred the contact to a second dealer; don rich Ford CO inc (221 e montgomery st, villa rica, GA 30180) who diagnosed that the grille shutter and the sensor fuel injectors had failed and needed to be replaced. The contact stated that the vehicle was repaired; however, the failure persisted. The vehicle was towed to a third dealer; pugmire Ford (1 Ford way, carrollton, GA 30116) who diagnosed that the valve body and other unknown components of the transmission needed to be replaced. The contact stated that he has sustained back injuries due to the failure but had not sought medical assistance. The manufacturer referred the contact to NHTSA for assistance. The vehicle was not repaired. The failure mileage was approximately 23,600.
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.