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kevin, Ford Mechanic
Category: Ford
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Experience:  7 years
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have 2005 5.4 3v f250 code po345 knocking or rattle in timing

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have 2005 5.4 3v f250 code po345 knocking or rattle in timing cover. high mileage. vt cam sprocket? how to check?
This is most likely the cam phasers, heres a procedure we use to determine if its the phasers.


The 4.6L 3V and 5.4L 3V variable cam timing (VCT) feature may emit a light knock in normal operation and is audible only at idle speed, with a hot engine (gear selector in park / neutral). However, it may be masked by or mistaken for other noises generated from either injector firing or a malfunctioning valve train as described above. The noise does not affect performance or durability of the part.

VCT phasers may knock at hot idle. It may be heard inside the passenger compartment, or the wheel well area. Some light noise is normal. The engine may require a cold soak overnight for a full diagnosis to effectively be made at hot idle, particularly when a VCT phaser is suspected. The knock is not prevalent at cold temperature.

To test for VCT noise:

  1. Place the transmission in park or neutral
  2. Bring engine oil temperature to 160° F (71° C) or above as indicated by the scan tool "EOT" PID.
  3. Allow engine to idle, and determine if noise is noticeable.
  4. Set engine speed to over 1200 RPM (if noise is a VCT knock, the noise should disappear).
  5. Return engine speed to idle (verify knock returns).

    If the noise intensity is more than a lightly audible knock at hot idle under 1200 RPM at engine operating temperature, replace the cam phaser

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Customer: replied 6 years ago.
would this set code po345? noise seems louder on pass side but code is fordriver side . replace both phasers?
I would replace both, this can set this code, I actually had this same problem on a F150 with the same engine, this code can also be due to a faulty alternator but in your case I believe that the phasers are at fault. The phasers were the fix on the F150 that had the same symptom as your truck
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