Improper air-to-fuELRatio is the most common cause of engine knocking noise in a Ford Fusion. Fuel burns unevenly when the internal combustion chamber doesn't get a proper balance of fuel and air. If left unaddressed, damage to the piston and cylinder wall will be resulted. Inaccurate fuel octane rating is another cause of knocking. If You use fuel that has too low of a rating, the fuel can ignite before a spark is actually provided by the spark plug. A lean air-to-fuel mixture is another cause. This is typically caused by a faulty oxygen sensor, fuel pump, mass airflow sensor, or fuel injector. When there isn't enough fuel multiple detonations are required because the mixture doesn't burn as fast as it should.
Check alternator mine sounded like it lost a couple of rod bearings. So i buoght a salvage motor put it in and knocking as soon as it started up. So pull that motor go exchange for another one put it in the car and d**n its knocking tooi took of the belt and the knocking stopped i noticed metal shavings coming out of the front of the alternator swapped it out and the knocking stopped
James J.
April 10, 2020
The knocking sound often occurs when the air-fuel mixture is incorrect
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