XW4E - AE, AG is the casting number for 1999 only because it's the only XW block with a 12mm det sensor boss. It has a provision for the oil feed to the right side cylinder head (Figure 4) to use with variable valve timing (VVT) although it's not being used. There are also coolant port changes that occurred on the right side that required a new design head gasket. A coolant port flange with two boltholes can be found on the top of the block used in the Lincoln LS and Mazda MPV. This flange is plugged for all other applications. This block now has two boltholes in the trans mount flange area on the right side above the dowel (Figure 2). Typically you will find the casting number for this block in the lower area just above the bedplate.
2000-'05 Taurus/Sable, Escape/Tribute, Lincoln LS, Jaguar S & X, Mazda MPV and 6.
XW4E- BA is the casting number for 2000-'02 and you will find the casting number high on the block just under the cylinder head deck or along the top of the trans mount flange on the right side. In 2003-'05 casting number 3W4E came on the scene. I have seen Broadcast Code engines that were 2003 and 2004 and had XW4E blocks. If you're a purist I leave it to your own heart; otherwise I consider the blocks to be fully interchangeable.
In fact, the blocks are identical to the 1999 block except the det sensor now has 8mm threads. Since this is nearly identical to the det sensor situation with the 4.6L Ford, I would assume that the same companies that provide those adaptors and tooling should be able to do the same for the 3.0L Duratec.
1996-1998 Taurus/Sable RFF Valvetrain
Right and left heads are c/n F5DE with different suffix numbers; the cylinder heads are different from side to side. These heads have six round intake ports (Figure 11).
1999 Taurus/Sable RFF Valvetrain
Right and left heads are c/n F7DE cylinder heads with different suffix numbers; the heads are still different from side to side. This right side cylinder head has a protruding ear to cover the oiling port for VVT, which is not being used.
2000 Taurus/Sable RFF Valvetrain
Right head is c/n YF1E and left head is c/n YL8E. These heads now have 3 oval intake ports, and still use a front water pump. This right side cylinder head has a protruding ear to cover the oiling port for VVT, which is not being used.
2001-'04 Taurus/Sable RFF Valvetrain
As with the 2000 models, the right head is c/n YF1E and left head is c/n YL8E. These heads still have 3 oval intake ports, but now have a rear water pump driven by the left intake cam. The right side cylinder head has a protruding ear to cover the oiling port for VVT, which is not being used.
The front covers are a big piece of the proliferation puzzle on these engines and can be a vital tool for identification. For even more information about the variety of covers used on the Duratec engines, turn to Core Corner on page 28 of this issue.
There are two casting numbers (c/n F5DE-BJ and F8DE-AB) used for the first run 3.0L Duratec engines. These covers have a cam position sensor mount on the upper right side of the cover (left side of engine) and a crank position sensor mount on the lower left of the cover (right side of engine).
This cover (c/n 1F1E) was a mid-year introduction. There is nothing that confirms the 42-tooth timing components and this cover were introduced simultaneously but it seems likely. The tensioner mount moved from left side of the cover (right side of engine) to the right side of cover (left side of engine). The cam and crank position sensors are in the same location as the first timing cover but this is now a rear water pump engine.
You should read over the entire article.The 1999 engine can be a profit-eating shark, so make certain that you know which block casting you have to determine the head gasket set you are going to use.
Don't put early heads on the late blocks or they will leak.