Hi friends.

Searching forums but no good answers.

Bought this recently and it's missing so I'm going to replace plugs and wires.

Can you recommend some great plugs and wires?
Why do you like them?

Motorcraft iridiums?

Worried about breaking one off so going to spray some liquid wrench in there and let em soak.

Any tips and tricks? Some dielectric grease for the tips and anti seize for the threads?

Would love guidance for this first go around.

Hope you all are doing well. We deserve the best.
Appreciate any help and guidance.

Andrew

 

Motorcraft platinum plugs. Skip all the gimmick crap.

The 5.4 doesn't have plug wires, it's a coil-on-plug (COP) arrangement. Plan on a replacement boot/spring for each cylinder. You'll probably find you need one or two COPs, so it's usually best to troubleshoot the misfire BEFORE taking the rest of the stuff apart. Too often, the misfire is caused by the coil itself any there's no point in not addressing it first. No, do not replace all 8 COPS, it's a silly waste of money done by those who cannot troubleshoot.

 

Or by those that figure if a couple are bad, then others can't be far behind. And if you're like me, doing all at the same time saves you from going back in replace others. Heat and age are the biggest killers of the COPs.

When I replace shocks, I replace them at least in pairs. When I replace wheel bearings, I do them in pairs. Brake pads.... again, in pairs (sets really). Tires..... you'll never guess....

 

I'll have a couple coil packs at the ready. Don't really want to shell out for 8 if I don't have to. Might just do the 2 in the back to get started.
Best way to troubleshoot? Not seeing any obd codes but surely it's missing and my pre purchase inspection mentioned it.
However it's been awhile since I've done a scan.

Long day. Knew I had coil packs.

So how would you diagnose?
New to the Expedition. Explorers were my thing but couldn't pass up the deal.

Thanks.

 

Except that's a false assumption. If it were correct, some or all of the other 8 COPS on my V10 would have failed after replacing two of them back in 2013, the rest are original (155K). On my old 97 5.4L, I replaced a total of two of them over the course of 7 years and 120K miles that I owned it. It still had most of the original coils in it when I sold it with 195K miles on it.

Using such faulty logic, if you had to have a root canal, you'd do them all because the rest must obviously not be far behind.

Shocks, bearings, tires, and brake pads are all wear items, their replacement is expected when they wear out. Replacing them in sets, especially tires, shocks and pads, is done to try and ensure that performance and remaining life remains balanced. Coils are not wear items (they're not expected to "wear out" from normal use) although the plugs are. Hey, it's your money, feel free to spend it as you choose to.

It's not hard at all. Any scan tool that can read Mode $06 data will usually tell you which plugs are misfiring by examining the MISFIRECNT data. If you have an Android device, order a $10 BT OBDII adapter and get a $5 app (Torque).

Until the misfire rate exceeds a calibrated threshold, the PCM will not post a DTC or turn on the MIL. Such low-grade misfires can only be effectively troubleshot by digging into the computer's data. Ineffectively, by either guessing or just shotgunning it.

 

Go with the OEM plugs. Since they're good for 100K miles there's a pretty good chance you'll never change them again. Trust me, after changing the plugs one time you'll do almost anything to not have to do them again.

 

...yes motorcraft plugs. i tried a decent set couple yrs ago. engine was misfiring. i got 4.6 with 2 msd coil packs and motorcraft plugs on 97 expedition. she runs good. use OEM PLUGS

 

Alright oem. Check.
Need to diagnose coilpack issues.

Will a typical obd reader from orielly say or shucks give me the $06 readings needed to diagnose which ones are misfiring?

 

If you've got a code thrown, yes.

If the coil is still firing but it's not getting cleanly to the spark plug, will not show up as a misfire- because the coil is still firing. New boots may fix the issue- the plugwell may be filled with oil from a leaky valve cover gasket (or water from a recent engine wash).

 

It's not throwing codes so I can't diagnose. Being im replacing all the plugs...going to go ahead and replace the boots/springs while I'm in there.