Motorcraft SP546 Spark Plug Review

Motorcraft SP546

One of the biggest problems for owners of Ford F150 trucks using the 5.4l Triton V-8 with three-valve heads is premature failures and catastrophic engine damage resulting from design flaws in the factory original spark plug, SP515. These plugs are known to have failures with the grounding strap, causing bits of metal to fall into the engine which can cause all sorts of problems. Ford introduced this spark plug as a replacement in 2017. We bring you a Motorcraft SP546 spark plug review to show you if this is the solution to the factory problem. (>>> Find the current price on Amazon)

Motorcraft SP546 Spark Plug Review of Main Specs:

Motorcraft SP546 ‎sp-546 / pzk14fFind on Amazon

The SP546 is a fine-wire, platinum spark plug that is intended to handle extremely high temperatures inside the combustion chamber and provide long service life. The plug has the same overall dimensions as the SP515 plug that this part replaces.

Why Platinum?

A platinum electrode allows for superior transfer of electrical energy from the electrode to the strap, allowing for a powerful and consistent spark even at high RPMs when the plug is facing the most grueling work it does. Platinum is a rare-Earth mineral that is known for its superior conductive properties over copper and other metals used in spark plug construction.

Problems with Original Plugs

The original spark plugs for the Ford F150 Triton 5.4l V-8 engine were a brand-new design. The spark plugs were constructed in two pieces with the body of the spark plug being one section and the sleeve surrounding the electrode being a second component.

A common problem experienced by owners is that over time, carbon will build up around the electrode sleeve causing that portion to stick in the cylinder head. When attempting to remove the plug, the lower section frequently becomes stuck, causing the spark plug to break. That leaves the bottom portion still in the cylinder head requiring removal before installing a new spark plug.

How to Remove the Broken Plug

A call to the local Ford dealer lets you know that you are in for a serious repair bill if the plug happens to break on removal. In order to remove the plug, a special tool is required that extracts the broken portion from the head, allowing you to install new plugs. Repair shops charge between $400 and $600 to remove a broken plug.

You can purchase the tool separately and do the work yourself. The tool will cost between $40 and $80 depending on the manufacturer. You’ll notice this tool was designed specifically for this one engine, so this is a fairly common problem that should be addressed sooner rather than later.


  • Superior design over previous SP515 spark plugs
  • Eliminates the likelihood of catastrophic engine damage
  • Provides better power than stock plugs


  • One of the most counterfeited automotive parts in the world
  • No alternatives for replacements from better companies

Why the SP546 is Better

Motorcraft re-engineered the spark plug when they designed the SP546 to eliminate the weak spot joining the two sections. This means that once you install the SP546 spark plugs, you aren’t likely to have problems with breakage.

A Note on Counterfeit Parts

Unfortunately, thousands of sellers online have discovered that they can repackage inferior parts that are designed to look like genuine Motorcraft spark plugs and sell them for massive profits. Learning to spot a fake product is easy. You’ll want to look at the printing on the plug and the manner in which the ground strap is welded. Here is a quick video that illustrates the differences between an authentic part and a fake.

Tips for Installing Spark

Motorcraft SP546

There are a few little things you can do when installing new plugs to make sure you don’t have problems in the future.

Always use a small amount of Never-Seize when installing new plugs. This keeps the threads of the plug from becoming bound into the head and makes removal easier in the future.

You should also use a small amount of dielectric grease on the plug end that connects to the spark plug wire. This ensures you have good electron flow from the wire to the plug.

It is also a good idea to replace your plug wires at the same time as your plugs.


Replacing the spark plugs typically isn’t a big project, but with this engine, you’ll want to use care and be prepared for failure when removing original plugs. The best bet is to get authentic Motorcraft SP546 plugs as soon as possible and replace the originals with these upgraded parts. (>>> Check on Amazon)