Some 2005-2012 Lincoln Navigator vehicles equipped with a 5.4L 3V engine may exhibit an intermittent rattle noise/rough idle when at operating temperature. The issue is caused by oscillating cam timing. DTCs P0022, P0021, P0340 and/or P0341 may be stored in the PCM.
1. Using the IDS (Integrated Diagnostic System) scan tool or equivalent, monitor cam solenoid duty cycle and cylinder head temperature (CHT) parameter identification (PID).
a. Start IDS
b. Select Data Logger
c. Select PIDs VCTDC, VCTDC2 and CHT.
2. With the engine idling at normal operating temperature (CHT above 200 degrees Fahrenheit), apply the parking brake and hold the brake pedal firmly with the transmission selector lever in D. Raise engine rpm from idle to approximately 1,500 rpm and release the throttle. Does the engine exhibit a rattle type noise with a rough idle, and are the cam solenoid duty cycle PID values oscillating after rpm returns to idle speed? If yes, proceed to Step 3. If no, refer to workshop manual, section 303-00 for normal diagnostics.
3. Replace both left and right variable camshaft timing (VCT) oil control solenoids.
Variable camshaft timing solenoid……….….……8L3Z-6M280-B
LH cam cover gasket for 14-bolt cam cover…….7L1Z-6584-B
RH cam cover gasket for 8-9 bolt cam cover……7L1Z-6584-A
RH cam cover gasket for 14-bolt cam cover…..…3L3Z-6584-EA
LH cam cover gasket for 15-bolt cam cover…..…3L3Z-6584-DB
VCT solenoid to cam cover gasket 2005-2006….3L3Z-6C535-AA