Ford Mustang overheating problems

Filed Oct 21, 2026 · Engine · NY

Coolant intrusion caused by a crack in the engine block coolant leaking into cylinder 3, engine replacement needed. 50k miles on the vehicle.

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 29, 2026 · Electrical · CA · fire

A new Walmart-brand EverStart Plus 96R, 590 CCA automotive battery was purchased on August 4, 2026, and installed in a 2016 Ford Mustang Convertible. On the evening of September 26, 2026, my family and I drove the Mustang and returned home at approximately 11:00 p.m. The vehicle operated normally. There were no warning signs, electrical problems, overheating, or other indications of a mechanical problem. The Mustang remained parked and untouched overnight. At approximately 2:00 p.m., 15 hours later, on September 27, my daughter came into the room and told me that the car was on fire. Riverside County Fire responded to the scene. Fire personnel specifically asked whether the Mustang had been driven or worked on that day. I told them it had not. The vehicle had remained parked since approximately 11:00 p.m. the prior evening. Fire personnel continued to suppress the fire, investigated the engine compartment, cut the battery cables, photographed the vehicle, and advised me that the battery appeared to be the possible source of ignition.

Filed Sep 22, 2026 · Engine · FL

Engine coolant leaked into the cylinders. Overheating. Coolant leaked into catalyst. ODB Error codes attached . Independent service center replaced short block, see attached invoice. Engine light on.

Filed Sep 14, 2026 · Engine, Transmission · AZ

Head gasket blew, and car overheated immediately on the freeway, with no warning signs, and at only 43,000 miles when a failure like this should not occur. Had to find a place to pull over and be towed to avoid more engine damage. Both independent mechanic and Ford dealership has confirmed this. Official diagnosis is "Remove and replace cylinder head assembly and replace head gasket – coolant intrusion cylinder 1, P0316, P0301.” Apparently it's a known issue with this particular engine and has a pending lawsuit.

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 Aug 20, 2026 · Engine, Fuel system · AZ

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.

Filed Aug 13, 2026 · Engine · 124,000 miles · TN

The contact owns a 2019 Ford Mustang. The contact stated that while driving 40 MPH and depressing the accelerator pedal, the vehicle hesitated, causing the engine to overheat. The contact pulled over to the right side of the road and turned off the vehicle to allow the engine to cool down while waiting on a mechanic to arrive on the scene. An independent mechanic was contacted, and the vehicle was taken to Auto Zone to be diagnosed. The contact was informed that coolant had leaked into cylinders #2 and #3 before the failure occurred. The vehicle was towed to an independent mechanic to be diagnosed, and it was determined that the head gasket needed to be replaced. The vehicle was repaired, and the ignition coil packs and spark plugs were replaced; however, the failure persisted. The contact stated that the failure had occurred twice. The contact associated the failure with the federal safety agency Campaign Number: 25V828000 (ENGINE); however, the VIN was not included in the recall. The manufacturer was notified of the failure and referred the contact to the dealer for assistance. The approximate failure mileage was 124,000.

Filed Aug 11, 2026 · Engine · GA

2019 Ford Mustang with 3.2 EcoBoost engine has coolant intrusion into the engine thru a defectively made engine block. Diagnosed by the Ford dealer in Hinesville,GA on August 11,2026. Car has 52,731 miles on it and has always been maintained by the local Ford service department. Car is a daily driver, no abuse or rough driving. Car is available for inspection upon request Coolant intrusion can cause sudden engine failure, loss of power and sudden stoppage at any speed. Overheating due to loss of coolant, engine fire, loss of control of the car. Check engine light came on and engine ran rough on cold start up on [XXX] & i then took it in to be checked out by Ford service. Service advisor stated that this coolant intrusion is due to a Ford known defect in the EcoBoost engines; but that there has been no recall. Only solution he offered was to have a new replacement engine installed for about $13,500. I declined the replacement. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)