Some 2004-2005 f-150 and 2005 f-super duty, expedition, and navigator vehicles with a 5.4l 3- valve engine may experience difficulty with spark plug removal which may cause damage to the spark plug and leave part of the spark plug in the cylinder head. Action refer to the following service procedure for techniques to remove the spark plugs and extract broken spark plugs. Service procedure general spark plug removal to remove spark plugs without damage, it is necessary to adhere exactly to this procedure before removal is attempted.
1. Make sure the engine is warm (hand touch after cooling down). Caution: do not remove plugs when the engine is extremely hot or cold soaked. This increases the chance the threads could be damaged. Caution: be sure to wear safety glasses for step 2. 2. Remove the coil-on-plug assemblies and thoroughly blow out the spark plug wells and surrounding valve cover area with compressed air. 3. Back out the spark plugs, no more than 1/8 to 1/4 of a turn. Apply penetrating oil (aerokroil or equivalent) and fill the spark plug well just above where the jamb nut hex sits. A minimum period of 5 to 10 minutes of soak time is required. The penetrating oil will wick down to the ground electrode shield in this time. Do not work the spark plug back and forth at this point. Caution: excessive penetrant, or repeating the process several times with too much fluid, could introduce enough liquid volume to hydro-lock the engine. Caution: do not use air or power tools for plug removal. The plug must only be removed with hand tools.
4. Slowly turn the spark plug out. Some screeching and high effort may be noticed but, not in every case. The expected removal torque is about 33 lb-ft (45 n.M) but should decrease on the way out. If it is higher, try turning the spark plug back in a half turn, then back out again. If the turning torque still seems high, repeat the back and forth rotation along with some penetrating oil to reduce turning effort. Separated/broken spark plug removal if the plug does come apart even after following the general spark plug removal procedure, it will break in one of two modes: mode 1: the ground electrode shield is left behind as an empty shell (fig. 1 ). Fig. 1: ground electrode shield left behind as empty shell mode 2: the porcelain center and ground electrode shield is left behind and only the upper jamb nut comes out. In this case more soaking is required and long-reach nose pliers should be used to grasp and remove the porcelain center from the ground electrode shield (fig. 2 ).