My 2018 Lincoln MKZ with the 2.0 Ecoboost Engine incurred premature engine failure at ONLY 40k miles. My safety as well as other drivers’ safety at risk due to EcoBoost Engine in certain model year 2013-2019 Ford and Lincoln vehicles have an inherent design defect which makes them predisposed to leak coolant, including allowing the coolant to seep into the engine cylinder, which causes overheating and cylinder head cracking, and can cause the engine to misfire, suddenly stall, or even catch fire while driving. In April the car began to ‘shake’ at start up. The shaking was intermittent. After a few days of this, the check engine light came on. I took it to the mechanic (T&H) to have it looked at. They said the ‘shaking’ is the car misfiring at start up. They were not able to locate any leaks or identify the cause of the misfire. They code on the check engine light was Code P0301-Cylinder #1. During April and May the misfires have continued and got worse. I was going back and forth to T&H trying to diagnose the issue. On May 12th, while taking the kids to school, I went to pull out into traffic and the car would not accelerate. The dashboard lights said the engine was overheating. The car would not go above 10mph. Luckily my mechanic is down the street. They were concerned about excessive use of coolant and not seeing a leak anywhere. They filled the coolant, and I made a follow up appt in one week to do a borescope inspection. On May 19th, T&H did a Borescope inspection and visually confirmed coolant in cylinder #1. They provided me a copy of a TSB 22-2229 that states the engine block needs to be replaced. The cost of the engine block replacement was estimated at $8k. Engine failure at 40k miles is unacceptable. An engine block replacement due to a manufacturing/design flaw should be covered by Lincoln Motor Co as a goodwill repair regardless of warranty status.