Fai attenzione alle candele a due pezzi da 16 mm con filettatura alta di Ford Motorcraft che si rompono! Le candele di accensione originali del marchio Motorcraft installate in fabbrica in molti modelli recenti (dal 2004 al 2008) di camion Ford con motori V8 da 5,4 litri e V10 da 6,8 litri, motori Mustang GT 4.6 e V8 da 5,4 litri dal 2005 al 2007 e modelli Mustang GT del 2008 costruiti prima del 30/11/07) possono rompersi quando si tenta di rimuoverli!

I veicoli con queste candele includono: 2004 – 2008 Ford F150 2005 – 2008 Ford Expedition e F-Super Duty 2005 – 2007 (e modelli 2008 costruiti fino al 30/11/07) Ford Mustang GT con motore V8 da 4,6 litri (utilizza bobine di accensione 3L3E) 2005 – 2008 Lincoln Navigator 2006 – 2008 Ford Explorer 2006 – 2008 Lincoln Mark LT 2006 – 2008 Mercury Mountaneer 2007 – 2008 Ford Explorer Sport Trac F-53 Telaio del camper Le candele Motorcraft PZT 2FE Platinum hanno un guscio dell'elettrodo inferiore aggraffato che viene rivestito con

Anche la ruggine e la corrosione sul guscio del tappo inferiore possono causarne l'adesione. Quando si tenta di svitare la spina, il guscio inferiore si rompe e rimane nella testa. La rimozione del guscio rotto richiede uno speciale strumento di estrazione Ford, Snap-On o Lisle. Peggio ancora, se qualche frammento di guscio o elettrodo cade nel cilindro e non può essere ripescato, potrebbe essere necessario rimuovere la testa del cilindro per estrarre i detriti.

Molti esperti raccomandano di sostituire le candele originali Motorcraft prima di percorrere troppi chilometri (oltre 40.000 miglia). La sostituzione dei tappi a basso chilometraggio ridurrà il rischio che si attacchino e si rompano. Aspettare che le candele di accensione di primo equipaggiamento abbiano 100.000 miglia su di esse significa mettersi nei guai!

Se il tuo veicolo ha molte miglia (diciamo oltre 80.000) e le candele non sono mai state sostituite, potrebbe essere meglio lasciarle in pace. Le candele originali Motorcraft hanno un elettrodo centrale con punta in platino. Le spine dovrebbero durare fino a 100.000 miglia o più.

Molte spine in realtà vanno fino a 140.000 miglia o più senza problemi, a condizione che il motore non bruci olio e veda abbastanza guida in autostrada per mantenere pulite le spine (frequenti brevi spostamenti stop-and-go possono causare la rottura delle spine). Quindi, finché il motore si avvia e funziona bene e ottiene un normale risparmio di carburante (nessun malfunzionamento e nessuna spia di controllo del motore con codici di malfunzionamento), non è davvero necessario sostituire le candele.

Here's another thought. If you are planning on selling or trading your Ford truck or Mustang within the next couple of years (and it is running fine now), leave the spark plugs alone and let the next owner worry about changing them. The risk is if you attempt to change high mileage plugs and break off several plugs (which commonly happens), those spark plugs could cost you a lot of money.

Many Ford dealerships are charging $600 to several thousand dollars to change the spark plugs on the 5.4L, 4.6L and 6.8L engines that have the two-piece Motorcraft spark plugs. Why? Because the plugs usually stick and break, and it takes a lot of time and effort to extract the debris from the spark plug holes. In some cases, it may even be necessary to remove the cylinder heads to complete their repair.

Ford's Technical Service Bulletin 08-7-6 Ford Technical Service Bulletin 08-7-6 covers the recommended removal procedure for these spark plugs, as well as the repair procedure if one or more plugs break ( Click Here to View Ford TSB 08-7-6). NOTE: TSB 08-7-6 supersedes the earlier TSB 06-5-9 that also covered the same subject. The difference is that the newest TSB says to remove the spark plugs when the engine is COLD (at room temperature).

The older TSB said to remove the spark plugs when the engine was WARM (not COLD and not HOT). They theory was that a warm engine creates a little more clearance between the plug shell and cylinder head. But removing spark plugs on a warm engine with aluminum cylinder heads also increases the risk of damaging the threads in the spark plug hole, too.

How to Remove the Motorcraft Spark Plugs So They Do Not Break First, make sure the engine is at room temperature (COLD). Loosen each spark plug about 1/8 to 1/4 turn. Then Stop! Spray some WD-40 or penetrating oil into each spark plug well. Allow the oil to soak into the threads so it can loosen any carbon or corrosion around the electrode shell.

Wait at least 15 minutes, or longer (overnight is recommended if the plugs have over 80,000 miles on them). After the penetrating oil has had time to work, slowly loosen each spark plug, applying no more than 35 ft. lbs of torque to your wrench. If a plug sticks, retighten it half a turn, apply more penetrating oil, wait, then try again. The plugs may squeal and groan, but will hopefully come out without breaking.

Removing carbon from inside the combustion chamber prior to changing the spark plugs can also reduce the risk of the spark plugs sticking and breaking. Using Top Tier gasoline or adding a fuel system cleaner (such as Chevron Techron or equivalent) to your fuel tank regularly can help reduce carbon buildup inside the combustion chamber.

If you engine has a lot of miles on it, and/or is using oil, using a Top Cleaner treatment to remove carbon prior to changing the spark plugs is highly recommended. What To Do If You Break a Spark Plug If you break a spark plug, see the Ford TSB 08-7-6 to see Ford's method for removing the broken electrode shell from the cylinder head.

Here is a short video on how to use NAPA Ford Spark Plug Extractor SER 4663 Lisle Tool also sells a spark plug repair tool for these applications (part number 65600). To see the instructions on how to use the Lisle tool to remove a broken spark plug insulator shell, Click Here. The Lisle Tool is available online at Amazon and from Snap-On tool distributors.

Spark Plug Installation Do NOT reinstall the same Motorcraft spark plugs (PZT 2FE Platinum). Replace the original equipment spark plugs with one-piece spark plugs from Champion Spark Plugs(part number 7989), or similar spark plugs from NGK, Denso or Bosch. Several aftermarket performance companies (including Roush) also sell a stronger one-piece replacement spark plug for these engines that won't break.

Note: the Champion spark plugs require a larger 5/8-inch socket to install (the original Motorcraft plugs have a 9/16-inch hex shell). Apply nickel anti-seize to the outer surface of the lower electrode shell (the smooth part) before installing the plugs. Tighten the new spark plugs to 25 ft. lbs (34 Nm). Replacing the rubber boot that fits between the coil and spark plug is also recommended to prevent arcing that can cause misfires.

More Spark Plug & Ignition Articles: Spark Plugs Spark Plug Technology Why Spark Plugs Still Need To Be Replaced Spark Plug Wires Analyzing Ignition Misfires Spark Plugs & Ignition Performance Coil-Over-Plug Ignition Systems Ignition Coil Diagnosis & Testing Engine Won't Start, No Spark Diagnosing An Engine that Won't Crank or Start Click Here to See More Carley Automotive Technical Articles Be sure to visit our other websites: OBD2HELP Random-Misfire ScanToolHelp TROUBLE-CODES

Fonte: AA1Car.com