Change plugs or not?

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Whimsey

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My bought new 2002 F-150 with the 4.6 V-8 will be 10 years old in December. It has around 53,000 original miles. It still has the original plugs, cops and wires/boots. About 25,000 miles ago I retorqued the plugs to spec. I did not remove them only loosened them and torqued them tight. The engine runs great, plenty of power and real smooth and quiet. Rust is active on the truck. It's in a body shop to take care of again the doors and tailgate rust plus now the leading edges of the bed. The miles I drive aren't going to change. So it'll take 20 years to get to 100,000 miles. By then it'll be rusted too bad. This model year had the shooting plugs. It seemed that this happened more so on engines that had the plugs changed or with high mileage engines.

Rather than open up a "can of worms" I'm planning to leave them in. If I need wires, cops or boots I'll change them. Of course if a plug goes bad I'll change it.

Opinions or thoughts?

Whimsey
 
Don't know man. Replacing heads scares me.
I'd do as much research as possible.

Part of me says change them out. Only so that you can get as much as possible out of the engine before you have trouble.

Also, you might want to RESEARCH placing a dab of copper anti-seize (the stuff that is specifically made for aluminum heads) on the threads of the plugs to help them come out later in life. Run them in and out a couple of times by hand to spread out the anti-seize, but make sure you have nothing on the bearing surface before you torque.

Again, this make of FORD trucks scares the daylights out of me. Heads are expensive.
 
i thought the 5.4 only had the spark plug blowing out of the hole issue?
 
With respect to your concern, I don't see a difference between swapping plugs and doing what you did, loosening and retorquing. That's assuming the plug issue you're worried about doesn't stem from cross-threading.
 
Believe it's caused by steel plugs galling to the aluminum heads & pulling the threads out. Anti-seize would be a smart move, unless the new plugs have the shiny coating that's supposed to act as anti-seize.
 
they don't need replacing unless the truck saw a lot of additives in the gas,
when you do change them do it with a cold engine and before changing them blow any dirt off around the plugs
 
Both the 4.6 & 5.4 blow plugs, have heard of several in the 60-80K range loosing original factory plugs... The re-torque should prevent that from happening but I'd consider changing them by at least 65K mi, as gaps have usually opened beyond specs...

Ford says not to use anti seize but I always do and have never had a issue...
 
I'd say they'll be fine for a while longer.

I just did the plugs on my 2000 F-150 with the 5.4 last year, because I needed to replace the intake manifold due to a coolant leak. I'd planned on waiting 'till 100k but it seemed illogical not to replace them when the manifold and all it's associated parts were out of the way. They were the original plugs and had approximately 75k on them at the time. Most were still in spec, though a couple were a few thousands over. I was pleased to see the bodies of the plugs had nearly no corrosion on them. The truck has aways had good power and idled smoothly.

I don't think the 4.6's had the same problems with the intake manifolds that the 5.4's did, but if you ever needed to remove the manifold thats the time to change plugs. It was as easy as changing plugs on an old inline six then! I did use never seize on the threads and was easily able to get my torque wrench on all the plugs.

I do think re-torquing them periodically is good maintenance.
 
If it runs good just run it, spark plugs don't age out.

I'd be worried about them getting welded into the heads but it sounds like you already loosened them up.
 
Originally Posted By: Whimsey
My bought new 2002 F-150 with the 4.6 V-8 will be 10 years old in December. It has around 53,000 original miles. It still has the original plugs, cops and wires/boots. About 25,000 miles ago I retorqued the plugs to spec. I did not remove them only loosened them and torqued them tight. The engine runs great, plenty of power and real smooth and quiet. Rust is active on the truck. It's in a body shop to take care of again the doors and tailgate rust plus now the leading edges of the bed. The miles I drive aren't going to change. So it'll take 20 years to get to 100,000 miles. By then it'll be rusted too bad. This model year had the shooting plugs. It seemed that this happened more so on engines that had the plugs changed or with high mileage engines.

Rather than open up a "can of worms" I'm planning to leave them in. If I need wires, cops or boots I'll change them. Of course if a plug goes bad I'll change it.

Opinions or thoughts?

Whimsey



The reason the plugs shoot is Ford's low torque spec. People have found 28-32 ft/lbs dry keeps them from shooting out. Don't fear the plugs.

http://www.f150forum.com/f72/97-03-v8-f150-spark-plug-change-93389/
 
I would also change them and you say the right thing when you said torque them. Even with that mileage there will be some build up on plug and some gap wear which the coils hate 100%. Keeping the gap wear down to keep load off coils is never a bad thing.
 
I think the threat of plugs being stuck is greatly exaggerated. I can't even begin to say how many 100k plus plugs I've pulled out of aluminum headed engines with hardly a problem. Yes, it can happen, but not like everybody says.

Manufacturers are putting coatings on their plugs (at least Champion is) for extended service now, unlike the old days.

I would leave them in there until around 80k. By that time the gaps will have started eroding and causing the occasional (unperceivable) misfire. Replacing them will help your engine and catalyst system last longer.
 
Originally Posted By: mechtech2
Eric - on THESE engines? There is a problem, for sure.


Fo' sho'

Get on any of the Ford forums that use either the 4.6 or 5.4 and you'll hear stories of how a little tick turned into a blown plug within a week or two...

At 91K mi, a friend had to soak the plugs overnight to get them out of his '01 F-150 Lightning... Those being supercharged, often have the threads packed with carbon that locks the plugs in place...
 
Originally Posted By: TFB1
Originally Posted By: mechtech2
Eric - on THESE engines? There is a problem, for sure.


Fo' sho'

Get on any of the Ford forums that use either the 4.6 or 5.4 and you'll hear stories of how a little tick turned into a blown plug within a week or two...

At 91K mi, a friend had to soak the plugs overnight to get them out of his '01 F-150 Lightning... Those being supercharged, often have the threads packed with carbon that locks the plugs in place...


Thats what I was going to say, corrosion is not much of a problem but carbon can be.
 
Originally Posted By: mechtech2
Eric - on THESE engines? There is a problem, for sure.


The 2 valve 97-03 motors had a much worse issue with the blow outs than getting stuck. The nickel coating on Motorcraft plugs makes there no issue at all. The 3 valve 04-08 motors have the major issue with getting stuck and breaking in the head.
 
Originally Posted By: TFB1
Originally Posted By: mechtech2
Eric - on THESE engines? There is a problem, for sure.


Fo' sho'

Get on any of the Ford forums that use either the 4.6 or 5.4 and you'll hear stories of how a little tick turned into a blown plug within a week or two...

At 91K mi, a friend had to soak the plugs overnight to get them out of his '01 F-150 Lightning... Those being supercharged, often have the threads packed with carbon that locks the plugs in place...


I thought that the 2 valve 4.6's would just spit the plugs out? That shouldn't have anything to do with not changing them. Maybe a torque issue from the factory?
 
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