Need to replace the spark plugs on my 1998 F-150 4.6. What brand & part # should I replace them with? What should they be gapped at? More important than that is how in the HE double hockey sticks (LL) do I get to the spark plugs? I opened the hood & started feel faint when I looked at it. (scary). The truck developed a miss today. I ran a scan on it and these are the codes it showed. dtc #02-p0304, dtc#01-p1000. Can anyone offer some help? Thanks. Chief Mike.

 

Do yourself a favor and bring it to the dealership and let them do it. Only put motorcraft plugs in a ford. Trust me I tried doing this and it is not easy. you need a swivel socket and a few different size extensions.

 

i changed my plugs once, and i dont know if ill do it again.....they r just hard to take out........and time consuming

 

Somebody else can figure out the codes (not to familiar with them)

But as far as the plugs go...Don't be scurred......... Its not to bad of a job if you have a little patients. Unclip, unbolt and remove each coil over. Find the right extension, I believe for the back it was a 6". Reach back with your hands and the plug socket with extension and drop it in the hole. Then maneuver the ratchet back there and crack it loose. Once its cracked loose, remove the ratchet and back it out by hand. When putting the plugs back in, I taped my extension to the plug socket, or its tough to get it out. Its best to lay a blanket or something over the front and lean in and over the motor. Takes about an hour.

Use motorcraft plugs. Not sure if its the same for the 4.6 but the 5.4 takes a sp-479 gapped at .54. Autozone carries motorcraft for about $3 each or something like that. No anti-seize and 28ft/lb torque. Dielectric grease at the boot ends.

 

did the plugs on my 01 5.4 and it had about 100k on it. all plugs came out easy except we had one plug pop out on me and pulled the thrads with it. i would take it in, my father in law took his 05 in the dealer pulled 5 out of the 8 threads with the plugs so let them deal with it. about $800 bukcs for the job

 

Theres a big difference in the 2v and 3v 5.4L plug issues. On your truck (01) it was common for them to spit a plug if it wasnt torqued properly and worked its way loose due to the lack of threads. There is a TSB that addresses and fixes the issue. A simple fix with some easy maintenance really. The 05 would be a completely different story, it didn't pull the threads out, the plugs broke off at the shield because they were a poor design.

On the 3v 5.4L with those plug design issues, yes... it was best to take them in unless you like fishing for parts out of your heads. But he has a 98 4.6, no issues removing or installing plugs if it hasn't spit one out previously. Only issues with his is the access isnt the best, but not at all even close to impossible.

 

The OP's 4.6 doesn't have coil overs, it has old school wires. If you can't find the plugs, follow the plug wires back from the coil packs. They are on the INTAKE side of the valve covers.

You have a miss in #4, which is the last plug back on the passenger side. I bet you have coolant or water leaking into the well.

 

If your going to service, make up your mind now that you will learn before impatiences takes over. Otherwise pay big time for the job.
You need some tools to make the job as easy as possible.
A plug socket with a rubber insert, extensions and a rachet to begin with.
You have 2 coil packs with ignition wires from them to each cylinder.
The plugs are located under the plug boots, deep in a 'well' to get to the combustion chamber of an over head cammed motor..
The 306 code is cylinder 6 the second from the front on the driver's side.
The 1000 code is not a trouble code and will go away some time after the 306 code trouble is cleared.
As for plugs, use the factory speced type but others with the correct heat range will work fine.
You will hear disagreement on this but you make the decision.
There is no magic in plug makes as long as they are the same physical design and heat range for your motor.
Good luck.

 

Hey GLC, You are right on about # 4 cylinder having a miss. Looked up code myself. GLC what do you mean there might be coolant or water leaking into the well? I guess I will tackle changing the plugs myself. Thanks everyone for your help. Chief Mike.

 

304, not 306, Blue.

Mike, pull the #4 plug wire and use a mirror and flashlight to look down in the hole. If it's wet or full of crap, it has to be cleaned out before you pull the plug or you could foul the cylinder. You could have a coolant leak or condensation dripping from the A/C accumulator or water dripping from the cowl, with any of those #4 is the one that takes the brunt of it.

You may want to get new wires - OEM Motorcrafts are $70 at rockauto.com ($160 at the dealer). For plugs, the 4.6 should take SP-432's.

 

Changed the plugs and wires on my '97 4.6l many times; not all that tough. The back one(s) on the pass side are a bit of a pain because they're under the cowl and they slant to the rear; driver's side are much easier because they slant forward. Might have to unbolt the power steering pump to get at one.

Use only Motorcraft plugs and wires; these engines are very sensitive to these items.

Jim

 

Im not sure if they are imbedded into the motor like the 5.4lts?

but they are very easy to do maybe not the first time learning but when I did mine I removed the Injectors line (be careful not to destroy the o-rings but if you do theyre cheap to replace.) then then remove the Coil packs and use an extension to just get them lose.

Heres the best tool out of everything in your garage..
Grab a garden hose preferably (can buy a short one for cheap at your hardware store) and cut a good foot distance or what ever you feel happy with (making sure the inner diameter is a good size for the plus, just check with the replacement) Stick it down the hole pushing the plug into the tube, and pull them on out.

Same idea for putting the new ones in, twist the tube and pull it out carefully.

 

I use a magnetic spark plug socket followed by a 2" extension, a universal, then a 4" extension. If the tools want to come loose and leave the socket behind, tape them together with black elect. tape. If you can't get the connector loose on #4 COP, tape a small nut to the end of a pair of needle nose pliers. If any of the connectors break off their latch, use 3 small tie-wraps to secure them.(one around the male connector, one around the female side, and one to cinch the two together). I use Motorcraft Platinum plugs $3.50 ea. The first time I did it I swore I would never do it again. I guess now after 3 times I'm numb to it.

 

Guys, pull the fuel rails. Four bolts total and 5 minutes. It takes hours off the job and you don't need swivels, etc.

 

Before you remove the spark plugs, use some compressed air and spray it around the plug hole and inside of it too. Get all the junk out of there before removing the plug.

I've done plugs on both the 4.6 and 5.4 and so far have not had any issues. Take your time and use a torque wrench when putting the new ones in.

If you get pregapped plugs, check them ayways. I've had some out of spec.

I've always gone with Motorcraft as well.

When putting the new plugs in, use some rubber hose(fuel line etc...) and start the plug with it vs the socket. You'll use that with you finger to start the plug to insure you dont cross thread them.

Do one at a time so you dont mess up the spark plug wire order.

If you take your time, and it's your first time, it'll probably take you 2-4hours.