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Replacing Troublesome Ford Triton 5.4L V8 Spark Plugs

Kopycinski’s Brain

Jay KopycinskiPhotographer, Writer

The Ford 5.4L Triton three-valve engine is a great powerplant and comes from the factory with Motorcraft platinum tipped spark plugs rated to last 100K miles. However, if you’ve blindly attempted to change the plugs as you normally would on your average V-8, or you called your dealer checking installation prices, you’ve most likely been surprised. Given the former DIY action, you probably found the plugs can break in the cylinder heads. Given the latter action, it’s not uncommon to get a $400 to $600 quote from a dealer to replace the spark plugs.

The spark plugs in these engines were a new-style plug with an extended electrode tip. They were used in the Ford 5.4L Triton three-valve engines from 2004 to 2007, and in some of the 6.8L V-10 engines of similar years as well. The relatively long spark plugs have an extended electrode and metal spark plug tip on the lower portion. Over time, carbon accumulates here and can cause the spark plug tip to stick in the cylinder head. Upon removal, it’s possible for the two-piece plug to break, leaving the lower half of the inner porcelain and the tip in the head.

Many of these plugs can seemingly be removed without breaking them, but one never knows until you try to remove them. The longer the plugs are left in the engine, the more troublesome they may be to remove, and possibly more likely to break off. There are numerous theories on how best to remove the plugs to have the least risk of breaking them.

Pre-cleaning the cylinder head carbon with injector cleaner run through the gas tank is easy and may provide some help. It’s debatable whether doing the work on a cold or warm engine is better, though Ford recommends a cool engine. We turned each plug one-quarter turn and then soaked the plug wells overnight with some penetrating oil. The next day we slowly turned each plug out with a hand ratchet. We’ve also seen mechanics use air impact guns to spin the plugs out rapidly, but we decided against that tactic.

Even taking pre-clean and soak precautions, and working the plugs slowly, we managed to break five of the eight plugs and had to use a Lilse spark plug removal tool to complete the removal of the broken plug tips. The tool worked great, but total time to do the job on our engine was about four hours.