2018 Lincoln MKC: misfire or rough idle

Filed Oct 7, 2026 · Engine, Transmission · FL

Rough idle at start up persisted as I got onto the road and caused near complete loss of drivability as "check engine" light appeared for the first time. Had towed to mechanic who replaced coils and plugs. One month later, check engine light appeared again. Brought back to mechanic who looked it over and said it was fine. Two weeks later, third apperance of check engine light. This time, I took to Lincoln dealership who ran appropriate diagnostics and confirmed one week later this is the coolant intrusion defect that will require a long-block engine replacement for $12,500. Car has 55,000 miles.

Filed Sep 16, 2026 · Engine · 73,617 miles · IL

The contact owns a 2018 Lincoln MKC. The contact stated that upon attempting to start the vehicle, the engine misfired. The dealer was notified of the failure. The vehicle was taken to the dealer, where it was diagnosed that coolant intrusion had resulted in the engine failure, and it was determined that the engine needed to be replaced. The manufacturer was notified of the failure by phone. The failure mileage was approximately 73,617.

Filed Sep 11, 2026 · Engine · NC

I own a 2018 Lincoln MKC equipped with the 2.0L EcoBoost engine. The vehicle currently has approximately 72,326 miles. The check-engine light initially illuminated and an OBD scan produced code P0303, indicating a misfire in Cylinder 3. No other diagnostic codes were reported. Following mechanical evaluation, all four spark plugs and ignition coils were replaced. Approximately 145 miles later, the check-engine light returned with the same P0303 code. The code was cleared to confirm recurrence, and approximately 111 miles later the check-engine light illuminated again. I subsequently took the vehicle to a Ford/Lincoln dealership for further diagnosis. The dealership determined that coolant is leaking into Cylinder 3 and advised that the required repair is replacement of the engine/long-block assembly, at an estimated cost of approximately $8,900. I have since learned that Ford issued Technical Service Bulletin 19-2346 addressing certain 2017–2019 Lincoln MKC vehicles equipped with the 2.0L EcoBoost engine that may exhibit coolant intrusion into the cylinders, an illuminated malfunction indicator lamp, and misfire diagnostic codes including P0303. The prescribed repair under the bulletin may require replacement of the long-block engine assembly. A search of the federal safety agency's recall database using my VIN does not presently identify my vehicle as subject to a safety recall for this coolant-intrusion condition. I am submitting this complaint so that the federal safety agency has a record of another 2018 Lincoln MKC 2.0L EcoBoost experiencing a dealer-confirmed coolant-intrusion failure consistent with Ford's published technical guidance. I am particularly concerned about whether this failure mode has safety implications and whether the population of potentially affected vehicles has been adequately identified. The vehicle had not exhibited significant drivability problems, rough cold starts, or other obvious warning symptoms before the recurring P0303 check-engine indication.

Filed Jul 31, 2026 · Engine · 37,500 miles · CA

The contact owns a 2018 Lincoln MKC. The contact stated that while driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken to a dealer where it was diagnosed and determined that there was coolant leaking into the engine, causing a misfire. The contact was informed that the long block needed to be replaced. The dealer informed the contact not to drive the vehicle out of town and stated that the vehicle might stall while driving. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 37,500.

Filed Jul 3, 2026 · Engine · NY

Misfiring and then smoke in tail pipe. Just hit 70,000 miles and the engine needs replacing. A defect that's been known since I bought the car.

Filed Jan 16, 2026 · Engine · MO

The check engine light came on and it would run rough when started. It was determined the number four cylinder head was cracked, allowing antifreeze to leak into the engine block. I bought the car new in January 2019. The problem appeared with under 57,000 actual miles. The car has always been serviced on time at the dealership. The cost to fix the problem with a new engine is approximately $10,000. I bought the car new so that I would not have problems. It is my only form of transportation. In researching, I have found this is a reoccurring problem on the echo boost four-cylinder engine since 2017. It didn’t matter whether it was low mileage or high mileage the cracks would appear. There had been a recall on later models, but no recall for the 2018. I believe it should be under recall.

Filed Sep 23, 2025 · Engine · FL

The engine light has appeared approximately in April 2025. The inspection advised that the engine code indicated a misfire in cylinder 4. The engine rough idles when started. The coolant loss is extensive due to an engine issue and must be constantly filled.vwe were told by, iPaul's Repair shop, that upon calling Ford, that there was a Lincoln technical service bulletin re: the 2 liter eco boost engine. It was re coolant intrusion into the cylinders. Service bulletin # 19-2346. We have also replaced the spark plugs and coils. The engine light still came on with the same issue. It did not solve the problem of a DEFECTIVE ENGINE.

Filed Sep 4, 2025 · Engine · FL

I am writing regarding my 2018 Lincoln MKC, VIN # [XXX] which is experiencing clear symptoms of coolant intrusion into the cylinders. These include low coolant levels, white exhaust smoke, engine misfires, and a rough-running condition. According to **Technical Service Bulletin 19‑2346** (the federal safety agency ID 10169807, dated December 20, 2019), this issue is a known defect affecting MKC models with the 2.0L EcoBoost engine and recommends replacement of the long‑block assembly to correct the problem. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jul 24, 2025 · Engine · MI

Dealer service technician states the a crack in the engine block is allowing coolant to enter the cylinder causing misfiring. This appears to require engine replacement with only 59000 miles on the vehicle. This is a common problem with the 2018 engine and could result in a fire.

Filed Jul 11, 2025 · Engine · NC

Check engine light came on at approx 54,000 miles with code of cylinder 2 misfire diagnosed as spark plugs and ignition coils need replaced. All spark plugs and ignition coils replaced May 11. June 23 check engine light on again with cylinder 2 misfire. Was told spark plugs and ignition coils need replaced again. July 9 spark plugs and ignitiion coils replaced. July 10 check engine light came on cylinder 2 misfire. July 11 car was diagnosed as needing engine replacement due to coolant intrusion causing rust in engine

Filed May 19, 2025 · Engine · CA

2018 Lincoln MKC with 112,700 miles hesitating with accelerating. There have been no check engine lights activated. Took to Ford dealership for inspection and they found coolant level low and confirmed shuddering/jerking when accelerating. Found that cylinder 1 misfiring and upon further inspection found coolant intrusion in cylinder 1. Recommended long block replacement. I found that this year model with Ford Ecoboost 2L engine has had frequent issues with the coolant leaking into cylinders due to poor design of this engine. Contacted Ford and asked for help with the cost to replace the engine block and was denied any assistance.

Filed May 7, 2025 · Engine · 69,349 miles · TX

The contact owns a 2018 Lincoln MKC. The contact stated that there was a misfire coming from the engine while starting the vehicle. While inspecting the vehicle, the coolant level was extremely low. The check engine warning light was illuminated. The vehicle was taken to a local dealer where the vehicle was diagnosed, and the contact was informed of coolant intrusion into the engine. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 69,349.