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Lesson 3: powertrain – FORD FCSD TECHNICAL TRAINING FCS-14000-DL User Manual

Page 48

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LESSON 3: POWERTRAIN

VCT Operation

VCT

The theory of operation for the 5.4L VCT is similar to the 3.9L VCT used on the Lincoln LS and 2004 Ford

F-150 w/5.4L.

The major differences are:

– The 5.4L VCT system controls both intake and exhaust valve timing because the 3-valve setup uses one

camshaft for both intake and exhaust valves.

– On the 3.9L, the VCT only controls the intake camshafts.

– Parts look different and are serviced differently (5.4L vs. 3.9L).

– Part names are different than those used on the 3.9L.

The VCT can vary cam timing within a range of 60 degrees of crankshaft rotation.

– Defaults to full advance.

– Requires engine oil at preset temperature before VCT will function.

2005 Expedition/Navigator New Model Technician Training

02-SEP-04

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