What, exactly is the Ford Modular spark plug issue:

[UptownSport]

You can see what Ford did, and speculate why they did it.


I'd guess they saved $15 to $20 an engine and went with three valves instead of four* per cylinder.

Because of central location and size of exhaust valve, the plug came too close to exhaust valve seat,
so they left the threads off sparkplug tip to make it fit.




This plug came out hard. As you can see, the threads are fine.
The problem is the unthreaded tip, it 'cokes up' between that tip and cylinder head.

Ford specified and extended spark plug service interval, giving lots of time to 'coke' before someone attempted to remove it.
So when you, or a tech goes to remove the plug, the the threaded part unscrews, but the tip breaks off and stays in the bottom of the really, really deep spark plug well.
Stuck.
I understand they make special tools to remove stuck tips, and that Champion replacement plugs won't break.
(So don't go to a Ford dealer, they'll install Motocraft)

Obviously any thread can get stuck, we all know that, but their design and material was just asking for problems.




In short, more valves broaden power band over a two valve head.

 

[user 37446]

Duh, I thought you were asking what the issue was vs. explaining it...  :-/

Good picture of the problem, well not the broken plug problem or the spitting plug problem but one of them anyways, however, please correct me but I don’t think the Econoline ever got the 3 valve, that was the cars and F series... The E series van from 1997 on is listed as a 2 valve.   :huh:

 

[user 37446]

From Wiki: begin quote

“Spark plug issues


2-valve 4.6 L, 5.4 L, and 6.8 L engines found in many 1997-2008 Ford, Lincoln, and Mercury vehicles may have aluminum cylinder heads with threads for spark plugs that are stripped, missing, or otherwise insufficiently bored out. Ford acknowledges this issue in TSB 07-21-2 as well as earlier TSBs. Ford's TSB does not state that this issue is caused by owner neglect. Ford's only authorized repair procedure for out-of-warranty vehicles is to use the LOCK-N-STITCH aluminum insert and tool kit. For vehicles under the New Vehicle Limited Warranty, Ford will only cover the replacement of the entire cylinder head; however, the Ford recommended spark plug service interval extends beyond the duration of the New Vehicle Limited Warranty.[69]

3-valve 5.4 L and 6.8 L engines built before 10/9/07 and 3-valve 4.6 Ls built before 11/30/07 found in many 2004–2008 Ford, Lincoln, and Mercury vehicles have an issue with difficult-to-remove spark plugs, which can cause part of the spark plug to become seized in the cylinder head. The source of the problem is a unique plug design that uses a 2-piece shell, which often separates, leaving the lower portion of the spark plug stuck deep in the engine's cylinder head. The 2-piece OE spark plug design is intrinsically flawed, thus making it susceptible to this problem. Ford acknowledges this issue in TSB 08-7-6 as well as earlier TSBs. Ford's TSB does not state that this issue is caused by owner neglect. The TSB provides a special procedure for spark plug removal on these engines. For situations in which the spark plug has partially broken off in the cylinder head, Ford distributes multiple special tools for removing the seized portion of the plug. Their TSB explains the multiple procedures required for handling the different cases/situations that occur when parts of plugs are seized in these engines. This repair is covered for vehicles under warranty; however, the Ford recommended spark plug service interval extends beyond the duration of the New Vehicle Limited Warranty.” End quote

 

[Gideon33w]

Note: You can replace the 2 piece plugs with 1 piece versions that wont break off in the head

 

[UptownSport]

Thanks for further info, tomorrow we start on their 6.0 diesels, then Thursday Audi 3.2/ 4.2 LoL

 

[user 37446]

Thanks for further info, tomorrow we start on their 6.0 diesels, then Thursday Audi 3.2/ 4.2 LoL

Yeah, I do see some vans with the 6.0 just waiting for some sucker to come along.  While I am not afraid of the Ford spark plug issue, I do have a healthy disrespect for the 6.0 problems. They are legendary and costly to bulletproof! There’s a shop in Georgia, I forget his name, but he’s on YouTube and has tons of videos and info on all things power stroke. He has no axe to grind on any of the models from the 7.3 IDI  to the present 6.7, just makes big bucks fixing them.  

I remember now it’s FordPowerstrokehelp.com.  Kinda entertaining watching all of the explanations, horror stories etc. If fixed right the 6.0 will smoke the tires off any Superduty but if not bulletproofed, watch out checkbook! 

 

[akrvbob]

There are two distinct problems with Ford Spark plugs. The first one was it spitting out spark plugs because of too few threads. The second one was after they tried to "Fix" the first problem and created the second problem which was breaking the plug off on removal.

In 2008 they finally fixed both problems and didn't create a new one.

 

[Weight]

Very important to use "carburetor cleaner" to soften the carbon build up. Then replace plugs with new redesigned versions. If changing plugs the first time, I would use a dealer or a major shop.

 

[mr_elijah_gardner]

I use a shop to change the plugs in my 03 5.4 mainly out of paranoia. I've never seen them do anything different than I would do. I have only had one of these motors but it's well over 300K and hasn't missed a beat. I think the plug issue in those years should have consideration taken during changes. I would not have it be a deciding factor in buying another one.

 

[UptownSport]

Number of  Ford later model vans in junkyard was striking.
Average truck at pick n pulls is mid-late 90's; later models stand out.
Dunno why, specifically- Most looked nominally intact.

Kinda sad, one had the big 'License Applied For' sticker, another was that JY's own runner vehicle- Gulp.


Of course, newest Dodge was like a '72, but it had gotten totaled.

 

[BinDerSmokDat]

Good pic.

I'd have heard tips ranging from changing plugs sooner than recommended intervals, using carb cleaner when removing them and even loosening them but not removing them if they feel tight, retorque and then loosen. Repeat a few more times then going for a drive.

Supposedly the last one helps loosen crud on the tips, then going for a hard, hot long drive knocks it off enough to remove them without damage.

 

[BinDerSmokDat]

Also, for everyone who may not realize, that 3 valve design was NOT used on vans.
So the only real issue to consider for vans is the stripped/insufficient threads on the two valve engines.