Greetings! I am new to the forum of the 15 to present. I finally left the 05 5.4L and upgraded to a 2017 3.5 Ecoboost engine.. My shop manual from my new-to-me- truck has not arrived yet and I am changing out the plugs with the SP578 (CYFS12YPT) plugs. I found on the Advanced Auto Parts website that the gap should be .031 but it does not say the torque for the plugs. Would someone be able to tell me what the NM or ILB/FLB are on them, please?

Thank you!

 

Spark Plug Torque: 133 lb·in (15 N·m)

 

don't know want those plugs are but I would make sure they are iridium

 

The 2017 Owner's Manual for the 3.5L Ecoboost shows Motorcraft SP-534 as being the correct spark plug and gap is .030-.033 in. (0.75 - 0.85 mm).

 

I think those have been replaced with SP-578.

 

Thank you for the help.

 

I was finding the 578s were replaced by Ford in my searching as well. The truck only has 48,000 miles but the plugs were tough to remove. I have heard the coating on the new plugs make them easier to remove. That was mot my experience. Anti-sieze on them all before putting the new plugs in.

 

NGK makes Motorcraft iridium plugs. They do not recommend using anti-sieze:

https://ngksparkplugs.com/en/resourc...ut-spark-plugs

 

This ^^ Do not use anti seize, this is not the old 5.4

 

I don't ever want to deal with a seized spark plug, so I use a small amount of antiseize on my plugs. It doesn't take much, and I don't care if the plugs supposedly have a coating that works. I know antiseize works, as I have been using it for over 40 years. And have never had an issue from using it.

That said, there's always the flip side consideration that the plugs are unlikely to seize with the 30k mile change interval I choose on my 3.5. I noticed slightly longer crank times and a slightly rough cold idle that new plugs resolved. The rumor that the 3.5 is hard on plugs appears to be correct to me.