PERA'S Core Corner: Looking For Leakers In Ford's Duratec 3.0L Engines - Engine Builder Magazine

PERA’S Core Corner: Looking For Leakers In Ford’s Duratec 3.0L Engines

Living in a home that was built in 1910 is a bit like living in a piece of history, and the character that goes along with it is truly fulfilling.


Yet a home this old does bring its own challenges, so during the past month or so I have been replacing the remaining cast iron water pipes with copper ones. If any of you have experienced the joy of doing this type plumbing project you learn very quickly about how the proper amount of heat in the right place will literally leach the solder into the joint to seal it properly – or not. It becomes obvious where you failed to do so once you open the main water valve and you suddenly realize you have a leak.

That is exactly what can happen with the 3.0L DOHC Duratec Ford engines. In particular, those engines manufactured for the 1999 model year vehicle applications may have a greater tendency to leak.

It seems that engines built prior to 6/15/1999 used one head gasket and cylinder head/block combination and after that date used another. All of the casting numbers and details will be coming in an article later this year but for right now we are going to give you the basic information and images to keep you from having a leaker.


There are three different areas which clearly identify which head gasket is which and a small change was made to the coolant port area between cylinders No. 2 and No. 4 on the right bank.

If the wrong style head gasket is used you will have a coolant leak to the exterior of the engine, which on initial start up changes your shoulder posture from bold and robust to hunched over and distraught, usually with a small moan connected to it. So before that happens let me give you that “one thing” you need to know: if you have an F5 or F7 block use the early gasket; if it is an XW block use the later gasket.


Let’s take a look at the pictures and I will show you why. First compare the head gaskets early and late (Figure 1), noticing the three different color boxes on both gaskets, and corresponding expanded views with the same color borders (Figures 2, 3 and 4). All the pictures show the early view on the top and late view on the bottom. Then look at the expanded view of the cylinder head (Figure 5) and you can see the minor difference in the castings.

Put the wrong gasket on the wrong head and you’ll have your leaker. Look for a detailed engine article on the 2.5 and 3.0L DOHC Duratec engines in September issue of Engine Builder. I would like to thank Shai Dhanani and his staff at Yamato Engines, Bellingham, WA, for their assistance with this information.

For technical questions, contact the Production Engine Remanufacturers Association (PERA) at: [email protected]

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