SKILL LEVEL: Above Average – This repair requires a strong knowledge & experience level of auto repair and may be best done by an ASE certified auto technician.

If you own a Ford Truck made before 2007 and you ever got a very high quote to simply replace spark plugs, then this article is for you. Any shop worth its salt knows full well the issues with trying to remove spark plugs form the Triton V8 3-Valve engine and they will quote it accordingly. They also know that if you attempt to do this job yourself, you will most likely be back to their shop for a much more expensive job of removing or repairing the cylinder heads. The simple fact is that almost every time you attempt to remove these spark plugs, at least one of them breaks off into the cylinder head or worse the threads from the cylinder head are damaged or come out with the spark plug. This article explains the extremely common spark plug problems on Ford V8 engines. Their are 2 different issues to address: The first is one or more spark plug(s) broken off or stuck in the cylinder head, The 2nd is the spark plug has blown out of the cylinder head and/or the threads are stripped or pulled out.

The image below shows a spark plug(in the red circle) broken off inside the cylinder head

Broken spark plug in a Ford F150 Triton V8

Issue #1: Spark plug(s) stuck in cylinder head or broken off.

The OE extended spark plugs on these trucks are very long and the threads are not attached to the body of the spark plug which allows the spark plug to twist from the torque of trying to unscrew it from the cylinder head. This issue normally pops up when spark plugs are being removed & replaced for normal maintenance or misfire problem. Ford’s recommended replacement interval for spark plugs on most all of these affected vehicles is 100,000 miles. My own personal opinion is that waiting until 100,000 miles is asking for trouble and I believe waiting that long contributes to these spark plug problems. A spark plug goes through trillions & trillions of cycles during a 30,000 mile period, imagine how much abuse they go through in 100,000 miles. We see most trucks coming in with a misfire problem at around 60,000-90,000 miles. Also the cylinder head is aluminum, the spark plug has steel and other components and the 2 dissimilar metals will lead to corrosion. Every time I remove spark plugs from one of these Ford engines, the threads of the spark plugs are rusty & the base of the spark plug is rusty. The other thing that leads to these breaking off is that the OE spark plug is a 2 piece design and you can see from the images below the difference. This 2-piece design and waiting to 100,000 miles allows excessive carbon deposits to buildup between the lower electrode of the plug & the upper body of the plug.

motorcraft spark plug vs champion solid one piece design

Champion makes a spark plug that is 1 piece and while you should always try to put OE back on, In this case you may want to consider switching to Champion for their 1 piece design. So with all of that said, If you change your plugs at 30K intervals, you have a much better chance of avoiding the plugs breaking and you may even prolong the life of your ignition coils too.

Recommended steps to try and remove plugs without breaking them:

1. CHANGE THEM EARLY, Do not wait until 100K or until you have a misfire. I do a full tune up on my own truck at 30,000 miles. Of course I enjoy doing this type of work and don’t mind at all.

2. Let the vehicle cool, Ford specifically calls out in their TSB to allow the engine to fully cool and do not attempt spark plug removal on a hot engine. Soak all the spark plugs with a good carb/throttle body cleaner, the goal is for the carbon cleaner to weaken the carbon buildup that naturally occurs on the spark plugs, Spray all around the base of the spark plug and then let is sit for about an hour or more, Repeat as necessary, You can do this the night before and then again the morning of just to help get as much penetration as possible. A high quality penetrating oil should be used next like Aerokroil or PB-Blaster

3. Attempt to loosen each plug very carefully only about 1/4 turn. Use premium good quality tools that allow you to get a good solid strong and square position on each spark plug. Once you have them each 1/4 turn loose, then spray more penetrating oil and let it sit, This may sound like a pain, but if you can get the plugs out without them breaking, you have avoided some serious frustration and cost. The passenger side of the engine is where most breakage occurs so pay special attention their.

4. If a spark plug breaks and it usually will if you wait until 100K, then you will need one of these kits to remove the rest of it from the cylinder head. I have used the Lisle 65600 and it worked like a charm and it only took about 15 minutes. Dorman 42045 is similar, however I have not yet used that one and cannot say how it works but lots of them sell.

Issue #2. Spark plugs are loose or actually blow right out of the cylinder head and typically strip or pull the threads out with them.

Believe it or not this actually happens and it happens very often. Typical symptoms include very loud exhaust popping noise coming from the engine bay area, immediate misfire, and very likely a check engine light will follow shortly their after. Oh and one more symptom is that their is probably a spark plug or pieces of a spark plug laying around in your engine bay somewhere and your ignition coil may or may not still be attached to the top of that spark plug. Look at the coil tower next to the missing spark plug and the retaining bolt and a small piece of the ignition coil are probably still their. Ford has issued a TSB (Technical Service Bulletin) #: 07-21-2 which replaces TSB #: 7-15-2, This TSB explains that Ford has an authorized repair kit available so you can repair the stripped or missing threads inside the cylinder head instead of replacing the cylinder head. Below we have listed the expensive Ford authorized kit & the much cheaper aftermarket ones available.

Tools Needed:

Ford Authorized Repair Kit: Rotunda 302-00001 – Very Expensive

Aftermarket Repair Kits Available:

TimeSert 5553 – Professional Kit

NOT FINISHED, MORE TO COME