Hi all,

This is a cross-post from the Lightning forum re: a mechanical problem that may be an issue of interest to other F-150 owners.

Add my name to the list of trucks with blown spark plugs/ stripped cylinder heads.......

https://www.f150online.com/forums/sh...threadid=53172

Mine is a stock 1998 F-150 5.4L V-8 with 82,000 miles, bought in late August 1998.

I was driving 35 mph when a plug blew (don't know which one, yet, and I didn't think to ask the mechanic), and suddenly my F-150 sounds and runs like a two-stroke lawnmower engine.

Of course, the aluminum threads of the cylinder head were completely stripped when the threads holding the plug failed, and the plug came out explosively, and that means the cylinder head will have to be replaced; it'll be in the shop until next Friday (Labor Day weekend and all), and he estimated $1,500 to $2,500 for labor alone on this very labor-intensive job.

When I bought the truck, I had purchased the extended warranty for an additional $1k, but of course it expired 7,000 miles ago, which I'll easily put on in 3 months (I bought the truck almost 4 years ago to the day).

The non-Ford mechanic said he'd only seen maybe (3) blown plugs total in the 10 years he's been running his auto repair shop; that statement is what led me on a Yahoo! search to this site. I come here, only to find plenty of other F-150 owners who've had the same problem....

After reading other's posts, I now realize that the hiss I heard over the past few weeks and thought was a small exhaust leak was probably a compression leak around the plug.

These are the original factory plugs: I had not replaced them, so it can't be blamed on over-tightening, etc. Their torque was the result of FoMoCo torquing during manufacture.

I called the Ford dealership (quite accommodating folks before I laid down $36,000 to buy) and talked to a mechanic in the Service Dep't: he denied knowing of any problems or a TSB being issued pertaining to the aluminum cylinder head/plugs for any Ford car or truck (although he did mention changing a head for a blown plug on a Mustang just last week).

I'm obviously not a mechanic, but is it reasonable for an aluminum cylinder head to have only 4 threads holding the plugs in such a powerful engine? If this problem is as common as it seemingly is, isn't this something that should be subject to complaints to Ford, NTSB, and/or a recall, especially if Ford continues to offer no reasonable response?

Griping on a BBS is one thing, but where do you go to lodge a formal complaint in writing with either Ford (initially) or elsewhere?

All info and shared experiences are appreciated, as we're all in this together (like the door-crack and rear-window leak issue, amongst others).

PS the "take-home message" to other F-150 owners who haven't experienced this problem yet is to check your plugs regularly: they can (and do) work themselves loose from the cylinder head for no apparent reason, even after extremely low mileage, and then can fail catastrophically as a result, effectively totaling the engine.

Chris

 

Sorry to hear about your problem. I just changed my the plugs in my 5.4 and it doesn't seem like there was only 4 threads in the head. It took several turns of the socket to completely tighten the new plugs in place. I don't know how much blame can be placed on Ford, since the engine has 82K without the plugs ever being out. I sure hope you make out OK..Good luck.

 

Sorry to hear about your misfortune. One thing you need to consider, is that, even though there have been some other similar occurences such as yours, they are a small minority compared to the amount of engines and f-150 family vehicles that were built, so the mechanic could very well be telling you the truth when he says he hasn't run into this problem. One thing you have to remember, dealerships love waranty work, especially a large job like yours. They don't care if Ford is footing the bill.

 

Hi,

Thanks for the sympathy, guys; but I'll really need it after seeing the bill and writing the check for the non-warranty repair.

I trust this mechanic, recommended by my future father-in-law: he re-attached a disconnected hose on my fiance's car for free when they could've easily carried out an expensive repair without anyone knowing any better. An honest guy.

Mjhpadi, the Ford F-150 service guide recommends replacement of plugs at 100,000 miles with normal duty, and there's no mention of a need to check torque or perform periodic inspection on the plugs anywhere in the manual.

As a result, I don't think it's reasonable to expect there to be a problem, and/or a need. No TSB (technical service bulletin), service alert, or recall has been issued from Ford on this issue.

Naviman, I realize that BBS tend to attract consumers when there's a problem: perhaps it's human nature, but most people don't post to a BBS to say 'all is well'.

However, for every person that posts a problem, there's also hundreds, if not thousands, who have experienced the problem who HAVEN'T reported it, thinking theirs was an isolated event; that was my point in searching and posting on the web, to see if an unidentified trend or problem exists. I think there is compelling, if only circumstantial or second-hand, evidence of that.

Take a look at this 3-page thread, and you'll get the impression that blown plugs is a problem for the Lightnings, as well.

https://www.f150online.com/forums/sh...threadid=53172

I did a search on-line, and it seems TSB 98B33 was issued by Ford in Apr 99 as a general recall campaign - "Coolant/Cylinder Head Replacement". Does anyone know the details of what that was all about?

Thanks,
Chris

 

I had the same thing happen 2 weeks ago. Have you seen what the bottom of the plug looks like? The plug I blew out looked as if something had hit it so my problem might be something different. I was taking off from a stop light when it happened and it sounded just like you described. To make a long story short I am now waiting on a new motor to arrive. Sounds like you are in a better situation than I. Funny thing...I have 81,000 miles on mine.
Mike

 

Hi Mike,

Thanks for your report. I don't know yet where I am with mine, as they haven't done the work yet: the mechanic might find more damage once they start the work.

Doing a search on this BBS reveals more reports scattered thru different threads, including photos of the plugs and cylinder head, and reports of a tendency for the plugs to work loose on their own.

https://www.f150online.com/forums/sh...threadid=77813

Funny thread title for a not-so-funny problem:

https://www.f150online.com/forums/sh...threadid=77606

Here's some excellent fotos of the stripped threads (you'll see only 4-5 stripped nubs where the threads used to be, on page 2 of the thread):

https://www.f150online.com/forums/sh...threadid=79721

Apparently the steel plugs have 12 threads, but the aluminum head has 4-5 threads. Therefore, how long it takes to screw in the plug in isn't indicative of the cylinder head thread depth. There's a informative around here thread talking about design differences of the OEM vs aftermarket plugs.

I'll post more links when I find time; I'm off to the rental car office right now.

Chris

 

I can't believe Ford, they keep denying knowing about all this stuff. I called the quality yada yada whatever it's called, she said they didn't know anything about there being a problem with door cracks. I just about fell down, don't tell me after all these years there's nothing in her little computer about a door crack problem.


I've heard of this spark plug thing several times, so far only 5.4's. Is this happening on the 4.6's too?

 

Hi svtoby150,

Yeah, I couldn't help but note the irony of the Ford F-150 commercial that is currently running, where CEO Bill Ford says something like "you can throw anything at our trucks, and they can take it: they're built Ford-tough to work under any conditions you can dish out".

Mine has never pulled a trailer, never been off a paved street or highway, and this occurred under no load accelerating up to 35mph (unless you consider the A/C as a 'load'. 99% of my drive is normal-duty paved rural highway (no stop and go).

I haven't specifically searched for this being an issue with 4.6L, but perhaps that reduced horsepower is a blessing in disguise? I don't recall any 4.6L reports so far, just Triton 5.4L and the V-10.

Note that some of these accounts are from guys running SVT Lightnings with modifications, using nitrous oxide, etc. That obviously represents a greater stress on the unmodified stock engine parts like the cylinder head, but I'd think that the problems these guys experience would represent an amplification of the design problems and fundamental weaknesses that exist for stock models.

Chris

 

"Note that some of these accounts are from guys running SVT Lightnings with modifications, using nitrous oxide, etc"

Nitrous is one of the best and worst modifications to gain horsepower. It definitely gives you instantaneous power, but you have to really becareful with it. It can literally explode an engine.

Sounds like your situation is much different than that though. Guys running nitrous usually create their own problems. Have you discussed this with the Ford regional rep. I would bypass the dealership and see if you can get Ford involved. You may not get very far, but they may offer to help you some. Their reputation is important to them. Just make sure you have as many records of maintenance as you can and document everything also.

 

Chris,

I am kind of in limbo myself. The shop I took it to scoped that cylinder and told me the piston was coming apart. We are currently waiting for a remanufactured engine to arrive so the original motor still sits in the truck as of now. I plan to remove the head after the motor is out and take some photos of the damage and hopefully come to a conclusion as to what happened. I can't see how just blowing out a plug could cause piston damage without something else happening. I did hear a slight tapping sound like a lifter or valve 10 minutes prior to the blow out and I had never heard this before in the previous 80,000 miles.

I originally took it to the closest Ford dealer and they qouted me approx. $2500.00 for repairs in a best case scenario and without even opening the hood. Needless to say Ford is not working on my truck because I personally consider that ludicrous. Another $700.00 and I could get a new motor with a 5 year warranty. People can say what they want but it seems to me that there is a problem with these heads that Ford needs to acknowledge. Hope you end up better off than I.
Mike

 

Hi Mike, Navi Man and all,

Naviman, I'm not sure how to track down my Ford regional rep to discuss this issue, but I will look into it. Any tips of how to do this? I'm in Palmdale, CA (actually serving in the USAF, stationed out at Edwards AFB).

I'm in the process of learning about the mechanical issue right now, but will give direct negotiation a try after some research (and the long Labor Day weekend: I'm basically stuck at home without my truck anyway ).

I realize you catch more flies when using honey, rather than vinegar, for a lure; especially when dealing with a large organization that doesn't need to concern itself with the problems of an individual owner. However, I'd feel guilty if I solved the problem for myself, but turned my back on fellow Triton V-8 owners who may not even be aware of a potential problem......

I am looking around the web for other reports, and will compile them here for the sake of future owners who may find themselves in the same boat; at least a trail of breadcrumbs will be left.....

From pickuptruck.com, entering 'blown spark plug' in the search engine gives one relevant report of a low-mileage Ford (surprise! Not a Chevy or Dodge) V-10 with this affliction. This contains an unsubstantiated report of an awareness on Ford's part:

http://forums.pickuptruck.com/showfl...&Number=155196

More as I find it....

Chris

 

There's strenth in Number's.

Come on now, THERE HAS GOT TO BE A LAWYER AMONG US ???
How bout a freebie for the Community. Class Suite Action against Ford, the proof is in the plugs. And I totally disagree with whichever one of you think this is a rare ocassion. Read some post and open your eyes. I'd say there's close to a hundred people just on this site that have spit a plug already. Think of how many Lightning's they build a year and you do the Math.
A GOOD LAWYER AND I THINK FORD WOULD BE FORCED TO HAVE A RECALL AND REPLACE EACH AND EVERY ONE. MOD'S OR NO MODS.

I'd say we're looking at at least 10% and possibaly double that figure for all the people that don't even know there is a Lightning Forum to post on, or who simply fix it themself.

 

to truely determine the number of threads in the cylinder head all you need to do is count the number of rotations the plug requires...one 360 degree rotation is one thread and so forth...i think a problem that is being experianced here is the fact that there is no pre warm up of the cylinder head before plug extraction...a 60 second warm up is suffieciant...this allows the head to expand thus allowing the threads to expand away from the plug(aluminum has a greater expansion rate than steel over a temperature/time span)...mentioned is the fact that the plugs should be retourged, this is true,and should be done at every change and is a given with any high performance engine or severe duty power plant

 

Hi Rob_02L and TexfordD,

Rob, I think you're on the right track about strength in numbers, and proof being in the number of reported problems and in cylinder head design.

I'm no lawyer, but I'd guess that in court it would come down to a question of, is it reasonable to design a powerful engine like the Triton 5.4L V-8 with only 4-5 threads on an aluminum cylinder head? And even if it is, is it reasonable for Ford to fail to recommend a periodic check of spark plug torque? Especially in light of these reported problems?

Problem is, getting this issue to court is no small matter, and a rag-tag group of consumers is not sufficient to get this matter addressed....

Surely Ford must track repairs performed at their dealer's service centers, and would be expected to identify trends after carrying out statistical analyses? But that's trusting a huge corporation to police itself; can anyone say 'Enron'?

This potentially is a huge issue, much bigger and $$$ than the door crack thing. If Ford admitted a problem, they'd probably have to pay for engine replacement for a significant number of individuals who've already experienced loss due to blown plugs and destroyed cylinder heads (with the F-150 being the most popular truck, if not vehicle, in the US).

And in the event of a recall, what fix could Ford provide?

I'd argue that a recall designed to check torque, and warn consumers of the need for having spark plug torque checked could save significant $$$, since once damage occurs the expenses are great. Unfortunately, the burden of that expense is not being felt by Ford, but by the consumer.....

TexfordD, there's no reason to guess how many threads are in the spark plug cylinder head bore: enough people have pulled their cylinder heads after blowing plugs and stripping the threads, and it's pretty easy to count threads in an undamaged bore, once the head is out and on the way to the junkyard. I posted a link to some photos of the head (see above).

But if what you say is true, it seems that Ford needs to check spark plug torque in the factory during initial insertion on the assembly line, AND once again AFTER the engine has been running and the cylinder heads and plugs have sufficiently warmed up. Of course, we have no way of knowing what Ford actually does in the production plants, but if getting to the plugs is as difficult as everyone on this forum says it is, then perhaps the root problem is that this difficult and time-consuming (but important) extra step is being skipped by Ford during assembly?

A post on the difficult access to the last two plugs, and the result:

http://www.ford-trucks.com/dcforum/97up/1368.html

Worst case scenario for Ford (and all F-150 owners) is if 4-5 threads are truly insufficient to withstand the stress of expansion, and it's NOT an issue of improper torqueing at the factory: then a recall would require re-design and replacement of ALL F-150 cylinder heads, and that could hamstring Ford ($1,500 in labor alone, and I think that's for one head only).

Can you say 'deny' and 'stone-wall'? I bet Ford can.

On a side note, can a Lightning owner please check their service manual and see the recommendations for: a) replacement of spark plugs, and b) any mention of checking torque periodically?

Perhaps the worst aspect of this is the loss of confidence I've experienced in my truck and Ford: I love my truck, and bought it specifically because it was "Ford-Tough" (which on second thought, is just meaningless advertising: it's saying a Ford is as tough as a Ford. Well, duh: I'm as tough as I am, too).

And all of you who think you aren't effected by this issue: remember, it may just be a matter of time for you, and hopefully you won't be stranded far from home with your family, or towing a load up a hill, or passing in a tunnel or two-lane highway (or worse) when it occurs.....

And if it happens, and you make it through it without an accident occurring, you'd better have a spare $4k sitting in your bank account, since Ford won't offer anything by way of compensation.

Remember: I didn't know of this issue, and wasn't effected until a week ago.

Chris

 

I just lost a plug this weekend. Same problem. Of course I was 600 miles from home and towing a trailer. 53,000 miles on the clock. Ford refused warranty. My aftermarket warranty will cover it but only if we use a used head. They refuse to cover the cost of a new head.
The repair quote is $2800.

I had also noticed a slight ticking noise a couple of days prior to the failure. We ruled out an exhaust leak. It sounded more like a lifter or a rocker arm.

Take note if you hear this noise!