Spark Plug Replacement Questions

[TXLS]

My wife's '03 LS V8 just turned 100K miles. I would like to change the spark plugs, but have a few questions before I dig in. The car is dead-stock, and will remain so.

1. From my searches here, it looks like OEM plugs are the preferred choice. What, exactly, are the factory plugs: brand, P/N?
2. Are these best purchased at Ford, or are they something that is available at parts stores?
3. Any tricks or tips to changing the plugs, that may not be covered in the FSM?
4. Any risk of coil damage during the operation? If so, what are the things to watch out for and avoid? (my coils were all replaced under warranty).
5. Anything else you can share with me? I only want to do this once, and preferrably without breaking anything.

Thanks!

JD

 

[dNyce LS]

When I recently did mine, I used a 1/4 inch ratchet, 4 or 5 inch extension, and a swivel socket (think its 7mm).

I'm sure you can get the plugs at a parts store, just call them to see if they stock them.
The plugs should be motorcraft (pretty sure there platinum tip, that's what I used). I used autolite so I don't have a motorcraft p/n

When you remove the connector out of the coil, slide it straight back because a tilt on it will break it(believe me). And when pulling the coil out, be sure to not pull the connector while pulling it out

Be sure to check the gap!

 

[TXLS]

When I recently did mine, I used a 1/4 inch ratchet, 4 or 5 inch extension, and a swivel socket (think its 7mm).

I'm sure you can get the plugs at a parts store, just call them to see if they stock them.
The plugs should be motorcraft (pretty sure there platinum tip, that's what I used). I used autolite so I don't have a motorcraft p/n

When you remove the connector out of the coil, slide it straight back because a tilt on it will break it(believe me). And when pulling the coil out, be sure to not pull the connector while pulling it out

Be sure to check the gap!

Thanks for the tips! I may pull one plug just to read what it says, so that I get the exact same thing. Good info on the connectors; I know how fragile these things can be. Oh, and I always check gap on any plug I install; just silly not to.

Anyone else have any tips or information?

Thanks!

JD

 

[FASTLLS]

I run E3s..

 

[gcwimmer]

You might want to take a look at the TECH ARTICLES at the top of the page.

 

[Gus_Mahn]

How new are the coils? It may be worth changing the coil boots with the spark plugs. Strangely, the only boots available are from AC Delco. Inspect the white insulator on the plug for arc tracking. If there is any, replace the boot along with the spark plug. I believe this is the type of misfire that causes ETC failsafe mode. ALWAYS change the sparkplug with any coil replacement!

Gap the plugs 0.039"-0.044" Use anti-seize on the threads of the plug and a little dielectric grease in the boots. Make sure none of the clips break on the coil to the wiring. If they break, you can wrap a zip tie through the primary wiring and around the coil, so it can't come undone. Obviously, if you find any oil on the outside of the spark plug, the Valve cover gaskets need replacing.

 

[TXLS]

How new are the coils? It may be worth changing the coil boots with the spark plugs. Strangely, the only boots available are from AC Delco. Inspect the white insulator on the plug for arc tracking. If there is any, replace the boot along with the spark plug. I believe this is the type of misfire that causes ETC failsafe mode. ALWAYS change the sparkplug with any coil replacement!

Gap the plugs 0.039"-0.044" Use anti-seize on the threads of the plug and a little dielectric grease in the boots. Make sure none of the clips break on the coil to the wiring. If they break, you can wrap a zip tie through the primary wiring and around the coil, so it can't come undone. Obviously, if you find any oil on the outside of the spark plug, the Valve cover gaskets need replacing.

Thanks for the reply. The coils are about 2-3 years old, and are functioning fine. I have an OBDII scanner, and recently had it connected to the car to check a MIL (not coil related). No codes are present, and the drivability is fine. I remember what a bad coil feels like from when they were dropping like flies a couple of years ago.

Good tip on the boots; I'll probably pick up a set to have "just in case". I'll also be on the lookout for oil in the spark plug wells. If I find any, I'll plan on a valve cover gasket replacement.

Thanks for all the tips. And, I did go read all the relevant Tech Articles; good information.

JD