I am writing regarding my 2019 Ford Mustang EcoBoost Convertible (VIN 1FATP8UH1K5171097 ). This vehicle has been maintained exclusively at Ford dealerships since new and has now suffered a major engine failure just outside the warranty period.

On Repair Order #:412713 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).

(Problem arises) Around 53,XXX miles or so I started getting a misfire at startup. Drove fine afterward but would misfire at cold startup every day. I hoped it would go away with occasional higher revs once warm, perhaps to clear out carbon buildup. The engine light came on after a few days and my OBD2 scanner said cylinder 3 misfires were detected.

(Diagnosis) After researching online, and seeing my coolant was below the minimum level, I sadly confirmed that I did have a crack/gap leaking coolant into the engine. The exhaust was also white at startup momentarily and smelled of burnt coolant. Luckily the oil looked clean and unaltered.

(Temporary solution) A bottle of K-seal worked great for about 5 months until the problem returned. My neighbor, a former Ford mechanic, said to bring it over ASAP to inspect. He was somewhat familiar with the issue and said I would likely need a new engine since this problem was likely from the engine block which would need replacing!!!!!!

(FINAL SOLUTION & SALVATION!) My neighbor looked up my warranty info. My factory power-train warranty was valid until 5 years or 60,000 miles. I had 58,806!!!!!!!!!!!! He told me to book a service appointment immediately! As long as the service ticket was written before that milestone I would be covered by Ford. After 1 week in a service center I had a brand new engine, bolts, spark plugs, coolant, oil, and belts. ALL components, diagnostics, and labor were COMPLETELY COVERED by FORD!!! At nearly 60,000 miles I have a brand new updated engine in my car. Though I was upset their product couldn't initially hold up I am more than pleased with the result!

(Epilogue) If you have a power-train related issue with your Ford or Lincoln product, don't hesitate to reach out to a certified trusted Ford center. If you are within the limits of the warranty issued, they should have a fix for you. Check the reviews and experiences for best results.