Best replacement spark plugs?

[amyrvik]

Rough Running Sport Trac

Hi ya'll. I'm glad I found this site it seems to be similar to the site I frequent for info on my '78 Triumph Bonneville.

I have had this vehicle for about 3 years as a gift from my Dad. It has been a good truck overall except on cold start-up it runs rough and has a buzzy sound from the motor. I don't know why it does this and maybe the forum can help me. Lately I did put in some "Heet" to dry up any water in the fuel. It seemed to help but I am skeptical about its real effect.

I have a set of Taylor spark plug wires I plan to install but I think I will put in new plugs at the same time. Are the Iridium plugs worth the extra cost?

Appreciate your input to my questions.

Alan
Collierville TN

 

[rumpledoll]

The SOHC 4.0L V6 uses a waste spark ignition system. In this system there are only three coils rather than the six coils in a conventional system, with two plugs attached to each coil and each plug firing simultaneously. Each plug fires once at the end of the compression stroke (for power) and once at the end of the exhaust stroke (wasted).

All the plugs on one bank fire from center to ground and all of the plugs on the other bank fire from ground to center. The factory platinum plugs are different designs between the two banks. One bank has a platinum center electrode with a regular ground and one bank has a platinum disk on the ground with a regular center electrode. You will see one bank has plugs that end in the "P" for platinum suffix and the other bank ends in "PG" for, presumably, platinum ground.

The reason for this is that the wear is concentrated on either the center or ground depending on the electron flow. Because one cannot buy the single platinum on ground plug in the aftermarket, Ford specs a double platinum plug (that is, a plug that has a platinum center electrode and a platinum disk on the ground electrode, motorcraft suffix "PP") as a replacement part.

I would recommend doing just that, buying a good quality double platinum plug for the V6 explorer. At 60,000 miles I pulled my original plugs and they all were worn from the factory gap of 0.052-0.056 to ~0.063. They all could be used longer if gapped, but were showing some decent wear so I replaced them with double platinum plugs (Champion brand in my case).

Remember to pull plugs on an aluminum head engine like the 4.0L V6 only when cold, use anti-seize compound and don't over torque them.

Rumple

 

[Marinerman]

The SOHC 4.0L V6 uses a waste spark ignition system. In this system there are only three coils rather than the six coils in a conventional system, with two plugs attached to each coil and each plug firing simultaneously. Each plug fires once at the end of the compression stroke (for power) and once at the end of the exhaust stroke (wasted).

All the plugs on one bank fire from center to ground and all of the plugs on the other bank fire from ground to center. The factory platinum plugs are different designs between the two banks. One bank has a platinum center electrode with a regular ground and one bank has a platinum disk on the ground with a regular center electrode. You will see one bank has plugs that end in the "P" for platinum suffix and the other bank ends in "PG" for, presumably, platinum ground.

The reason for this is that the wear is concentrated on either the center or ground depending on the electron flow. Because one cannot buy the single platinum on ground plug in the aftermarket, Ford specs a double platinum plug (that is, a plug that has a platinum center electrode and a platinum disk on the ground electrode, motorcraft suffix "PP") as a replacement part.

I would recommend doing just that, buying a good quality double platinum plug for the V6 explorer. At 60,000 miles I pulled my original plugs and they all were worn from the factory gap of 0.052-0.056 to ~0.063. They all could be used longer if gapped, but were showing some decent wear so I replaced them with double platinum plugs (Champion brand in my case).

Remember to pull plugs on an aluminum head engine like the 4.0L V6 only when cold, use anti-seize compound and don't over torque them.

Rumple

Sounds good and I'll try it, but what did you gap your double platinum's at? Thanks.

 

[jlrapp8]

what are the best autolite or motorcraft plugs?? they have so many different ones. i have a 02 mountaineer with 4.0 AWD

 

[jlrapp8]

which spark plugs should i use? there are so many different autolite and motorcraft ones? thanks 02 mountaineer 4.0L

 

[BrianDye]

Im gonna get the 4$ MotorCraft ones from Autozone, Im the 3rd owner of my 92, i think the plugs have been changed maybe 3 times, its almost at 240k, so im doing a couple hundred dollar tune up, new plugs, wires, distribution cap & rotor kit, fuel filter, etc, hoping my rough idle when i start it up warm goes away

 

[rumpledoll]

I gapped them within the factory specification range of 0.052" - 0.056".

Rumple

Sounds good and I'll try it, but what did you gap your double platinum's at? Thanks.

 

[Marinerman]

I gapped them within the factory specification range of 0.052" - 0.056".

Rumple

Thank you. That's what I did.

 

[cyress]

I just bought the NGk Iridium IX Plugs...anything on those plugs?