Hello all - it's been awhile. I recently sold my 96 F350 and am in the market for another truck. I'm looking for a 98-2003 3/4 ton truck. I will be towing a horse trailer 1-2 times a year. I only put a couple K miles on a truck a year. I'd go V8 or V10. I'd like to stay with Ford but am concerned about the stuff I've been reading about the spark plugs blowing out or seizing up in the cylinder head. Is this a legit concern? If it is, do you think it would be reasonable to ask a sellor if the spark plugs have been replaced and things modified to prevent future problems? I don't want to be paranoid but if there is a legit problem with the plugs I want to go in with eyes wide open. Thanks

 

If you're unsure, change them out yourself when you get the truck. You could ask the owner if he's had any issues with them or any corrections/modifications made to fix a blown plug but I wouldn't let it hold you back from buying a truck if you find a good deal.

I never had an issue with the plugs in my 2000, and I had 10 of 'em.

 

Buying the truck and than removing the plugs brings a risk of discovering previous monkey job. I would pay the shop to do compression check as PPI and give them new plugs to put when everything check OK

 

That's not a bad idea. I've heard the plugs can be in there so tight they break when removing. I've read the 99-03 (maybe other years) engines were designed so not alot of spark plug thread grabs onto the cylinder head. Also heat/cooling effect of aluminum creates the potential for plugs blowing out. Is it a matter of routinely checking the plug torque? I also heard the OEM plugs break easier. Any recommendations for alternative plugs? Thanks for any info.

 

The breaking concern is more associated w/ the 2005+ 3valve engines, so breaking them shouldn't be a huge issue in the year range you're looking at. I believe the self ejection feature was corrected or at least helped in 2002 or 2003 when they added more threads to the head. Hopefully someone more knowledgeable about the 2valve engines can give more detail on that.

 

03 and 04 5.4 and 6.8 had the longer threads i believe..05 is when u have to worry about breaking them off.

 

Thanks for the info on the spark plug year range. It will help in my truck search.

 

Don't know if this will help but I have a 2000 5.4 that I bought used from a mexican construction company who bought it from a rental company. So there's no telling the **** it's seen. But when I changed the plugs, they didn't give me any trouble at all. I changed the coils some time later and they seemed to be the bigger issue when it came to the engine running smooth with correct power. Neither plugs nor coils were hard to remove, but if I had to choose one that blew out I'd go with the coils. Hope this helps.

 

Plugs if not changed will have a tendency to break when removing, due to carbon build up, weird type of plug. On my recently purchased 2000 F350 V10 104,000 changed all plugs with no breakage, original set also. Very careful to not force if felt like sticking and work carbon build up off.

If the plug should snap there is a tool which is made to remove plugs and I have seen it work great. Never used myself. What little I know if that is the biggest issue you have against possibly buying, find out if plugs have been changed recently and or change immediately just have access to tool or a shop do it that knows what they are doing.

After changing I would not let go over 50-70 K without replacing and should have no problem.

Stay Safe Drive Sober
Westy

 

There is a ton of information about this on the web. I first heard of it in the fall of 2010 during a long trip from Oregon to eastern Canada, when on Cape Breton Island a friendly stranger pulled up alongside me in a beautiful newer F250 SCREW and casually asked if my truck had spit the #3 spark plug in my 5.4L yet. It hadn't, but he definitely had my attention. We got home without a problem, but since then I've done extensive research, added a few tools to my collection and recently checked the torque on my plugs. My 2-valve engine has only 35,000 miles on it, and I wasn't expecting any problems, but I needed to know since I pull a small fifth wheel and didn't want this to happen while towing.

I pulled all 8 ignition coils and checked the torque on my plugs. None of them moved at all as I tested them up to 20 ft-lbs. I didn't go any higher than that, since I didn't want to over-torque them, just make sure they were good and tight. I was surprised by the torque, since the Ford factory spec is 7-14 ft-lbs. I was expecting them to turn at least a little bit, but none did. So either Ford changed the specs, or the dealership increased the torque before I bought the truck. I bought it new in 2003, and have no service done except for oil changes. BTW, the sticker on my engine shows it was built in Windsor, Ontario, Canada in November 2002. Thus I probably have one of the engines with just a few spark plug threads in the head. Ford changed the head design for the 2004 model year and went back to lots of spark plug threads. Unfortunately the spark plugs in the 2004 - 200? engines tend to break off during removal - but that's another story....

Thus my truck appears to be OK, at least in the spark plug torque department. In doing the internet research, I discovered a few things to think about if you are looking to buy a used 1997-2003 Ford with a 4.6L, 5.4L, or 6.0L engine. These engines have an aluminum head with just a few threads holding the spark plug. The threads on the spark plug are steel, so as the engine heats and cools the difference in expansion and contraction of the steel versus the aluminum can lead to loosening of the spark plug if under-torqued. Over-torquing can also cause spark plug thread failure.
* If the spark plugs are under-torqued, they can work loose and be spit out of the engine. This usually also breaks the ignition coil-on-plug.
* If the spark plug is under-torqued and simply un-screws, it can be replaced and properly torqued with no harm done to the aluminum head. This seems to be rare - usually there is head thread damage.
* If the spark plug is under-torqued and has wobbled around in the aluminum head threads without unscrewing, eventually the aluminum threads wear down to the point that the spark plug makes a loud ticking noise and eventually spits out, breaking the coil-on-plug too. This seems to be the usual case. In this case the plug can't just be replaced and re-torqued, but an insert of some kind has to be installed in the head. Ford recommends the Time Sert, but there are others out there. I personally would have this done by an experienced mechanic, but some owners say they have done it themselves with good results. At least one company has specialized in fixing this problem - blownoutsparkplug dot com.
* If the spark plug has been way over-torqued, the aluminum threads in the head can be weakened. Again, the plug can eventually start to wobble and lead to aluminum thread failure.
* If the spark plugs are properly torqued and never come loose, over time they can seize to the aluminum threads in the head. Then when the plug is removed for normal replacement, the aluminum threads can be stripped. This can happen if too many miles are on the engine before plug replacement. The general consensus on-line is that the plugs should be changed about every 60,000 miles, not at the Ford-recommended 100,000 miles.
* If the spark plugs are properly torqued and never come loose, over time carbon can build up on the tip of the plug, and if the plug is just brute-forced out of the head the aluminum threads can be damaged. Again the general on-line advice is to replace the plugs at 60,000 miles to help prevent this problem.
* If the aluminum threads are damaged, in some cases an insert won't fix the problem, and a new head has to be installed. Having an insert installed is in the $500 dollar range, while replacing a head is several thousand.
* Assuming the threads in the head are in good condition, when replacing the spark plugs the general consensus on-line is to use standard Motorcraft nickle-plated plugs, NO anti-seize compound, and torque to 28-32 ft-lbs.

Another thing to keep in mind is that Ford made about 3 million of these engines from 1997 to 2003, and most people don't have the spitting spark plug problem. But enough do that many consumer complaints have been registered. If I were going to buy a used Ford vehicle in this year range with one of these engines I'd want to have it thoroughly checked out before I bought it. I suggest having a qualified mechanic pull the spark plugs and inspect the aluminum threads, then depending on mileage install new plugs. But in any case make sure the torque is right - not too little or too much, and no anti-seize compound.

I learned everything I posted here by spending lots of time on-line. These aren't my original ideas, and anyone facing this issue should do their own research, consult their own mechanic, and make their own decisions on what to do. As usual, your mileage may vary!

FYI this is my third Ford pickup. 1966 F150, 1974 F250, 2003 F250. Guess I'm a Ford guy.

 

My truck still had the factory plugs in it a 132k miles. It's a 99. As long as they haven't been over-torqued, You should be fine. I installed new plugs, and haven't ever had a plug spit out, nor has one ever been ejected from this motor. I sell Parts for a living, and carry an extra ignition coil before I'd carry a replacement die and plug.

The issue Mine had was rusted and corroded exhaust studs. 13 of them had to be drilled out of the heads. Cost me nearly 800 bucks with the tune-up and EGR pipe replacement, but worth every penny with the mechanic I had do it. I've had no other issues. I'd always pick a v10 over a v8 superduty.