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Home >> Ford >> 1990 >> Cutaway 7.3 M >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/O Codes - Diesel >> Engine Knocks
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Engine Knocks

  1. Ensure all engine driven accessories are operating properly and are not the cause of the knock. Verify that engine is not overheating. If engine is overheating, determine cause and repair as necessary. If engine is not overheating, go to next step.
  2. Momentarily loosen injector line nut on one injector one-half to one turn. Then tighten connection. Check each cylinder in the same manner. If knock is not isolated to a specific cylinder, go to ENGINE PERFORMANCE DIAGNOSTICS . If knock is isolated to a specific cylinder(s), go to next step.
  3. Check injection nozzle line(s) for kinks or restrictions. Replace any line that is kinked or restricted. Remove suspect nozzle(s) from engine and test. See INJECTION NOZZLE TESTING . Replace any nozzle that does not pass test. If lines and nozzles are okay, go to ENGINE PERFORMANCE DIAGNOSTICS .
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