The contact owns a 2018 Ford Fusion. The contact stated that while servicing the vehicle, the contact became aware that the coolant level was low. The contact stated that on a separate occasion, while driving 30 MPH, there was a knocking sound coming from the engine. There was no warning light illuminated. The contact stated that an abnormal coolant odor was coming from the exhaust pipe. The contact stated that there was coolant intrusion into the engine. The vehicle was taken to the local dealer, and confirmed that there was coolant intrusion into the engine. The vehicle was not repaired. The contact related to the failure of Ford Campaign Number: 21N12. The manufacturer was made aware of the failure and confirmed that the VIN was not associated with the recall. The failure recurred, and the contact parked the vehicle, and the vehicle was no longer driven. The approximate failure mileage was 76,900.