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Change Your Ford Spark Plugs Earlier to Avoid Costly Repairs

Some 2004-2005 Ford F-150 and 2005 F-Super Duty, Expedition, and Navigator vehicles with a 5.4L 3-valve engines may experience difficulty with plug removal. This may cause damage to the spark plug and leave part of the spark plug in the cylinder head, requiring an expensive extraction process, and in some cases, even cylinder head removal or replacement.

[caption id="attachment_971" width="670" caption="Broken Shield in Cylinder Head and Diagram of Shield Welded into the Head"]broken spark[/caption]

There are special procedures Ford has recommended in a Technical Service Bulletin (TSB) that may reduce the number of broken plugs. Unfortunately in the real world, many still break because the spark plugs were not changed early enough. Ford, like many manufactures, now recommends the first spark replacement interval at 100,000 miles. This extended mileage allows carbon and rust to build up around the metal ground electrode shield, and the shield “welds” itself to the cylinder head. Due to the design and extender reach of the spark plug, the technicians, no matter how careful they are, cannot predict and/or feel if a plug is going to break until it happens. This is frustrating to both the consumer and the shop, as the cost to extract (depending on how many are broken) can easily double or triple the cost of the spark plug replacement.

[caption id="attachment_972" width="670" caption="Broken Ford Spark Plugs and Spark Plug Diagram"]broken spark and spark plug diagram[/caption]

Our recommendation is to change the plugs earlier than the manufacture recommends. We have found that a 75,000 mile interval is a safer bet.

If a spark plug does break, we have the special tools required. Unfortunately, we also have the experience of extracting many spark plugs on these types of engines. Not a month goes by where we don’t field a call from a frustrated customer, saying that Ford has told them the only repair is to replace the cylinder heads.

So if you have this type of vehicle or if you experience a repair facility telling you need heads replaced, give us a call. We can help.

Images: Convoy Auto Repair, AGCO Auto


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