1. How do I change the spark plugs on my 2006 E-250 with a 4.6L?

I couldn't even find them. I couldn't find the spark plug wires either. I found some thin wires going to something that seemed like the most likely thing to be attached to the spark plugs.

I did some research and I think those things are called coil over plugs and they may be attached to the spark plugs.

2. Do I need a special tool to get them off?

3. Do the wires typically need to be replaced for a complete tune-up? How can you tell if they need replacement?

4. Do the coil over things get replaced?

How do you know if they need replacement?

5. What is the correct gap for the spark plugs?

By the way, what's the recommended change interval for plugs and wires and those coil over things?

 

1. 7mm 1/4" drive socket with a couple different lengths of extensions will remove the bolt holding the COP (coil over plug) down. Then you can pull off the COP and a 5/8" plug socket with a couple sizes of extensions will get the plugs out. You need to pull the doghouse on the inside and open the hood, pull the air box and work from both inside and outside to get all the plugs. If the COP pulls out but the boot remains on top of the plug, you can spray some WD40 or similar down the boot and thread in a large bolt the size of the opening on the top of the boot and pull with that. Sometimes it's a wrestle, but I've never had a boot I couldn't pull with some patience. The new plugs should be coated with anti-seize and torqued with a torque wrench (13 ft-lbs I think).

There are no plug wires, thankfully. Only small wires from the harness to the COP. I typically don't even remove the COP from the harness at the connector, just put it aside while I'm changing the plug.

2. See 1.

3. They don't often go bad, but if you find misfire codes on a particular cylinder then it might be worth changing the COP. You can swap it for the COP on another cylinder and see if the misfire moves if you have that kind of time to play with it, otherwise just change it.

4. see 3. only if they are misfiring. They don't often go bad. We've got lots of them with several hundred thousand miles without issues.

5. I think 0.055ish. It might say on a sticker on the radiator bracket.

Honestly, I doubt a private operator really needs to change the plugs ever. Although I'm not sure what the difference between the way we operate our vehicles is and how a "normal" operator does. We do a huge amount of highway 70mph, not much idling and around town. I've got a 2006 right now with 381,000 miles on the plugs and a driver just came into my office raving about how well that van ran compared to another one. It could be that a lot of idling and around-town driving would be harder on them but I still wouldn't change them much before 150k or something, regardless of what the dealer or anyone else recommends.

 

Can't argue a lot with Del's experiences---his fleet racks up a ton of miles on those vans. The only caveat would be his fleet is probably much more carefully maintained than the average driver, most of us not putting that many miles on two or three vans over a long period of time.

However my philosophy on plug changes in the Modular Motors kinda follows this:

-Nothing but MotorCraft plugs as spec'd for the particular engine and year.

-Nothing but top quality COP's, either from Ford or NAPA. Not cheap but if reliability is key better is better every time.

-NAPA/Belden USA-made COP boots #702418, about $5 each. Very rugged but compliant enough to effect a good seal both on the plug body and COP body too.

-Small dabs of dielectric grease inside both ends of the boot, a dab more inside the COP wiring harness connector cavity. More is NOT good in this use.

-Careful removal of existing plugs if previous change interval is unknown.

-Use nickel-based anti-seize on plug threads, torque to 23 ft/lbs with a good quality accurate torque wrench.

That's how I do it---so far no issues with plugs or COP's beyond normal maintenance issues.

 

Woah there Tex! I've seen a couple different figures for this - one set of plugs I bought had a number printed on the package that I think was like 13 ft-lbs, but I had a look in the actual Ford shop manual and the number there is 10 ft lbs. This is for the 4.6 and 5.4l 2 valve engines, 2006 year.... Doesn't sound like much but I haven't had any blow out.

 

Tex whoaing up here Mr Del.

Every time this subject comes up I just love posting this link: https://www.ford-trucks.com/forums/1...ead-heads.html

Its an eye opener to be sure. From that info along with my own experience the 23 ft/lbs isn't out of line at all.

Torque values lower than my settings won't cause blow outs but they do quite frequently result in plugs becoming loose in their holes. Whether that causes or contributes to them being ejected and hole threads damaged when they do go hasn't been effectively proved or disproved, at least not to me.

When the PI heads were introduced there was a bit more plug hole depth added which results in a few more threads. Even so proper installation is the main key to avoiding the blown out plug issue.

Its not wise to disagree with Ford's recommendation but sometimes field experiences suggest another way that might be more useful.

PS: E-Series never received the 3 valve heads so all those problems don't exist for us. Just an FYI, not necessarily related to this exact thread, no pun intended.

 

Thanks for the feedback, all.
My truck has 193,000 miles on it, mostly of New York City driving I think. I just got it 2000 miles ago. I'll pull a plug and see what it looks like.

 

Del and I disagree quite a bit as to plug change intervals but IF your driving is mostly city streets and IF those plugs have never been changed I'd highly recommend doing this ASAP or time permits.

IF those plugs are OEM removing them might be a challenge as they might have become seized in place due heavy carbon build up at inside the plug threads. There is a process for safe removal in this instance but it is NOT a "grab it n go" thing---takes a bit of time and patience.

 

I figure I'll pull one of them out for starters and see how it looks. I got PO3 codes on cylinder s 1 and 6, so I'll pull the cylingder 1 plug first. If it looks good, they're probably all good. But maybe I'll pull the plug in cylinder 6 too, to be sure. If one of them is bad, they're probably all bad.

What is the process?

 

Watch this video even though its mostly about the 3 valve head spark plugs. The important parts are those dealing with carbon build-up on the lower portions of the plugs. This can/does happen on any motor where plugs have been left in a long, long time.



This is also a good one to watch:

 

Good vids !
I wonder why Ford went this route on plugs?
Chevy's sure are easier