Hello,
I am new to this forum (actually this is my first post). I recently picked up a 2007 Expedition with 240,000 miles on it. Unfortunately I have no repair history on the vehicle and no way to get it. It has misfire issues on bank 2 and I was looking at replacing the plugs and coils. I have read a ton of info on the issues these engines have with plug replacement, and best theories on how to do it trouble free. I have also watched several videos on how to do it. Basically they break down into 2 different theories, Driving the engine until it is nice and hot and using a impact driver to remove the plugs while it is still hot, or soaking it heavily in a penetrate like PB Blaster overnight and then go in with hand tools and slowly working it out. It seems like in most of the videos they break #4 and #8 when they do it hot, and when it is cold they need to pay special attention and respray these cylinders when cold.

My plan is to change the plugs this weekend. First I am going to add Seafoam in the fuel tank and run most of the last 1/4 tank of gas out of it. Then I am going to run a can of Seafoam throttle body cleaner through it to try and clean as much of the carbon as I can from the system. Then I plan on changing the plugs.

So Should I do it hot, with my impact driver as soon as I shut it off?

Or should I turn each a quarter of a turn and then soak it overnight with some PB Blaster and attempt it cold the next morning?

With this many miles I am assuming that they have had to been replaced at least once, but I have been proven wrong on things like this before. I am hoping for the best but a local auto parts store will rent me the Lisle kit if I need it.

Any other best practices will be greatly appreciated.

Thanks,
J

 

NO--absolutely NOT! Since you don't know how long ago the plugs were changed---or if ever---this is not a good practice. You want the "feedback" from a breaker bar as that indicates how much carbon build up any one plug has accumulated over the unknown mileage.

YES, positively yes! I'd use something like Ford's PM-3 or equivalent, not sure if PB Blaster is as effective on this particular task. Its better than nothing at all so if that's what you have use it, won't hurt anything.

Once your COP is out carefully inspect the boot for any sign it has lost its ability to insulate the spark from arcing to the surrounding metal. Those are cheap enough--get a good brand---and wise to change if they look even a bit suspicious to your own eye. No doubt this has been covered in your reading and viewing---this is a good practice too.

Before you begin loosening the plugs use compressed air to clear the plug hole so no debris falls down into the combustion chamber. On that note when removing the wiring harness connector make sure the little orange or red seal remains with the connector---they've been known to fall into the plug recess and greatly impede fitting the socket firmly on the plug wrench flats---been there, done that and it is NO FUN!

Actually that first 1/8th or 1/4 turn out will tell you so much about the general state of the plug threads below the head. If they continue to twist out without a struggle or gut-pulling on the breaker bar proceed a bit slowly until they're all the way out.

I use a nickel-based anti-seize thinly applied to the new plug threads and torque them to 25 ft/lbs. Some disagree with this practice but over 300K miles accumulated on three different 5.4 engines this has served me well---use your best judgement here. The factory manual says 13 ft/lbs plug torque but there is no danger of stripping the plug hole threads at the higher setting. Others might suggest you don't need a torque wrench, to just "wing it..." but that's not my advice---I like knowing I've set the plugs to some known torque, not relying on guess work.

When installing the COP's use a dab of dielectric grease inside the plug end and just a little in the upper electrical connector recess too---this helps keep moisture out.

Changing plugs is relatively simple but it's helpful going into it with potentially needed parts and supplies at hand---nothing more frustrating than making one more trip to the parts store. I sincerely hope you have nothing but good luck with this---let us know how it turns out!

 

Thanks
for all the info. I will update you when I am done.

 

You're not done yet?

*ducks*

 

First time I did this chore it probably took me a good 8 hours---I was bouncing back and forth on other tasks as well but starting at 7am that 3pm came quicker than I knew. Even being so careful I still managed to break one of the COP connector locking tabs---just one mind you.

Typically we learn so much from the first time changing plugs we're far, far less concerned about doing it again.

 

Yepper, that's me, always quick with a kind word, helpful comments and encouragement!!

 

You're a right proper sorta bloke then---good on ya!

Once AltBike has completed this he'll get the humor---maybe?

 

Yeah, I hope so ... lol

 

Actually it was very easy. They all came out without any problem what so ever. They really didn't need to be changed. The coils were really the issue, but the plugs were the new Motorcraft 546 plugs and had been changed recently and only had maybe 10-15,000 miles on them at best. I had already gotten the plugs and coils, so I changed them all anyway to know they were good and done right. There were 4 different types of aftermarket coils on the truck. Looks like I am changing a VCT next.


Even though it was easy, I really appreciate the advice that was given here.


Thanks again.

 

Great news then!

Keep your old parts, assuming you have the space. I've toss known working parts out thinking I'll never again need or want them then a day after that something goes wrong........

 

wow, I've never heard of anyone suggesting an Impact on plugs. I'm glad you didn't go that route. I do my plug when the engine is warm, but with a 8" ratchet. Not an impact. Glad it all went well for you. Do them every 50k and you wont have to worry about stripping out your plug holes.

 

Yep, I have already started a parts bin for this truck. It was running so good I let my wife drive it and now the seat is stuck forward. I am 6'6" so that is now my next priority.

It clicks when I push the switch, but it doesn't move. forward or reverse.

Thanks again

 

Several places on Youtube have guys doing it this way. They appear mostly to be shops where they want to get it done the fastest most efficient way. Almost eveyone worked great, except for plugs 4 and 8.

 

Former dealer tech here.

My technique;
Start with a cold engine.
Remove coils (7mm with a swivel and 10" extension on 1/4" air ratchet)
Blow plug wells out with compressed air
Fill each plug well roughly 2/3 with brake clean
Blow plug wells dry (EYE PROTECTION!)
Reinstall coils (no bolts)
Pull codes and Mode 6 data for misfires.
Test drive
Perform coil stress test.
Remove coils
Use 3/8 impact, extension, and swivel to remove plugs. Remove #4 first, followed by #8
Use Lisle tool to extract any broken plugs as required
Use carb cleaner and nylon bore brush (10mm? from local sporting goods store) to clean carbon from plug bores
Light coat of nickle anti-seize on plugs, as per TSB
Install and hand torque plugs
Install coils.
Test drive.

No need to remove PCM except on *some* Excursions.

I used to subscribe to the "only cold, and only by hand" school of thought. I also used to break 4 or more plugs. I tried following the TSB to the letter and really saw no consistency in reducing broken plugs. It always sucked to have to tell a customer "I'm going to need more time (money) to complete this job," especially when you broke 6 plugs while following the TSB. The process I just outlined would consistently result in 2 or fewer broken plugs. IIRC flat rate time for a plug change was 3 hours, and following my process I could consistently complete the task in 2 hours, including extracting up to 3 broken plugs, as long as I didn't break #8 AND #4. customers paid less, I made more. Everybody wins.

 

Good input Freak007---I don't recall seeing too many other dealer techs here---good to have one on-board. So a few questions maybe......just curious, not challenging you at all:

1. Did you ever know the age or mileage on any plug you removed that broke or the head stripped out? Do you think that makes a difference whether plugs break or not?

2. Did you use a torque wrench on the plugs? If not how did you assure to what value they were installed?

Looking forward to your reply---this is a topic often discussed here, at least a million opinions what does and does not work.