clm65

I'm at about 90K on my Lariat with the 5.4L. I'm not having any issues, but figure it is about time to change the spark plugs. I understand the correct plugs are Motorcraft model SP509 (please correct me if I'm wrong). Should I be replacing the boots too? If so, does anyone have a part number for them? And should the springs/ignition wires within the boots be replaced too?

Thanks!

Spiky

Shouldn't have to replace wires or coils unless something is known to be wrong with them.

10F150-5.4

Just did this on my 2010 5.4 also. I'm the second owner, truck had just over 100,000 on it when i got it. I never touched them till it had 280,000 miles on it..lol. Allot i know . so they had at least 170,000 miles on them. It was starting to miss under hard acceleration. Not normal driving though. Anyway, i didn't need to change the springs or boots. Bought one just in case one broke during it all. They were all in good shape though. There was some kind of buildup around a couple of the back plugs, made it so a socket wouldn't get on them and seeing in the plug hole was tough. Held the cell phone over the holes and took a pic with the flash to see. Used a small but long regular screwdriver to bust up the build-up and blew it out after with compressor. Other then that went well and was easy. Truck runs like new. She's been super reliable. 286,000 miles now...never a single problem.

Chris

10F150-5.4

P.S. I used the motorcraft double platinum SP-509 like you said. It's alsowhat came out.

For a boot I got that at advanced auto. Carquest part # 35-7087. But didnt need it.

I believe there are two different ones too..may use different plugs also. Most are brown. Mine was. You'll need to check that.

clm65

10F150-5.4

I got them through advanced auto. Regular price was $9.19 each. I found an online discount of 20% and paid online...went to store a 1/2 hour after and picked them up. Again be sure you have the dark brown boots. Was told plugs are different if they aren't. Mine were very dark brown. Easiest to tell once you get one out. It most likely is.

$35 For a set is way cheaper then i could find. I'd be nervous of it, But could be legit.

10F150-5.4

Then again with ebay, if it's a well known seller with a high percentage of happy customers, I'd give it a try.

ModularFord

clm65

There are a couple of sellers @ less than $35/set. Most have good reviews and lots of sales. I did a quick google search of fake spark plugs on eBay, and only came up with a bunch of fake NGK plugs (no Motorcraft). I'll probably take a chance and pick a seller that has "auto" in their name.

10F150-5.4

When are you planning to do it? Let me know how it turns out. Curious if you have the same build-up in the back sparkplug holes like I did. Made it difficult to see why being in the back. Cell phone pic trick helped.