My 2014 with 3.5 has finally hit 30k; figuring it is time to change out the spark plugs - What's the best result and gap? I work at Autozone so I can source a lot of them easily and see a lot of iridiums in our catalog. I'm happy with what is in there but not sure? Thank you

 

get motorcrafts

 

unless you have a ton of performance mods stock motorcraft, should come correctly gapped but I still check just to be sure. Dont use anti-seize on plugs

 

i'm not sure what MC are in there and the gap so I can check?
- can someone tell me? thanks

 

The number required for your truck should be pre-gapped.
If you do get a number provided, ensure you don't damage any coatings when you start bending them around like we did before sparkplugs because so fancy.

Tip: use a universal joint on your extension during removal to reduce risk of snapping a plug. Use a shop vac on blow mode or used compressed air to blow debris out of the plug well after removing the coil/boots.
One thing about these modern motors if the plugs become easier to change than years past!

If you decide it's become too complicated to find a plug gap, you are quite early at 30k, you can postpone the replacement for 2 more years at your rate. I actually drive slightly more miles than you.

I purchased motorcraft plugs from AutoZone when I changed mine a couple years ago (2016). I checked 2 plugs and they were gapped properly so I quit checking as I was likely to do more harm than good.

 

30k they really probably dont need to be changed unless you're noticing an issue.

there have been some threads about the gap, can probably find if you search because I believe it changed at some point (got a little tighter). if nothing else just make sure all 6 are basically the same. you do have to be careful with iridium - they're brittle and it's highly recommended you DONT pry against the electrode to move the ground strap

 

I did mine in my 2012, 3.7 a few months ago at 100k miles, as preventative maintainence. There was some slight wear, gap wise. I went back with same stock MCs.

 

Gap particulars are in the owner's manual.

(owner's manual) Don't have one -OR- would like a digital, searchable desktop document?
..

 

I run plugs 50-60k in my 2011 3.5. IIRC, previous change I re-gapped to .028 (before I knew not to mess with them). Most recent set came pre-gapped at .035, I think. The engine runs fine either way. I have been replacing the plug boots with plugs and using a little silicone grease in them too. If a boot stays on the plug when the coil is removed it is easily retrieved with long needle nose pliers. My first gen doesn't really seem to care much about gaps I've used, your newer engine may be a bit different.

It's going to be the little red unlock tabs on the coil connector that gives trouble if anything. Mine has two that broke and went missing. Luckily they are unnecessary.


2011XLT Screw 4x4 3.5l 3.55LS 175k miles

 

Why wouldn't you regap incorrect plugs? Do it properly and all is well. I'm not an expert on the 3.5EB, but....

I believe the current MC plug number is SP580. You should gap them to the smallest gap recommended in your manual.

Also note that MC is no longer iridium plugs, they are now double platinum. The original Ford (CYSF12?) were platinum on one side and iridium on the other. That changed. If people are wondering about why they burn up so fast, this is part of it. Also, turbos. If you want iridium, you may want to try a comparable NGK.