Tech Notes - Engine Builder Magazine

Tech Notes

Engine Builders: A camshaft and lash adjuster design change was made between the 2004 and 2005 Ford 5.4L 3-valve VIN 5 engines. AERA’s Technical Commitee says do not use 2005 model year parts when servicing a 2004 model year or 2004 model year parts for a 2005 model year. If parts are intermixed during a service repair, the engine may exhibit noise on affected cylinders and engine damage may result.

Camshaft differences between the 2004 and 2005 model years can be identified by the location of the variable cam timing phaser (VCT) pin notch in relation to the machining lug as seen on the end of the camshaft shown in Figure 1.

Figures 1, 2, 3

2004 and 2005 model year lash adjusters can be identified by the presence or lack of an identification groove cut into the lash adjuster boss shown in Figure 2. The 2005 model year parts will have this identification groove cut into the boss, while the 2004 model year parts will not.

NOTE: You should always confirm the engine model year by checking the engine tag located on the valve cover. A 2004 model year engine will carry code 4G-992-AA and a 2005 model year will be identified as 5G-692-AA.

Engine Builders: There is a cylinder head gasket design change for 2002 Chrysler PT Cruiser 2.4L VIN B engines. To improve the ability of oil drain back from the cylinder head and also improve crankcase ventilation on 2002 Chrysler PT Cruiser 2.4L VIN B engines, the hole size opening was changed. Beginning in 2002 this opening was reshaped to a much larger size.

A new cylinder head gasket was designed to fit the new cylinder head with c/n 04667086. The 2002 block was also modified to reflect the cylinder head revision. With the implementation of the improved engine oil return and crankcase ventilation (enlarged hole) it became necessary for the 2002 and newer head gasket revision.

The design change to the cylinder head gasket was made to cover the new larger crankcase ventilation enlarged hole. The hole, marked in Figure 3, right is between cylinder No. 3 and No. 4 on the 2002 head gasket. Only one of the oil drain back holes on the flywheel side is opened from a round hole to a slightly larger irregular shape.

The original hole was much smaller and is the reason the gasket will not fit properly on the earlier 2001 and down cylinder heads and blocks.

Although the earlier 2001 gasket can physically be installed on the 2002 head and block, it will leak oil from the uncovered oil return / ventilation hole in the cylinder head when the engine is run. It will also block openings. The oil hole between the cylinders is not a high-pressure oil passage.

The REVISED 2002 head/block may be installed on 2001 vehicles, so exercise caution when assembling these engines, as well as when buying cores.

For information on receiving all of AERA’s regular monthly technical bulletins call toll free 888-326-2372 or visit

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