After clearing out all of this new workspace in the garage, I was looking for a worthy first project so I thought I'd start by changing the spark plugs on my F150. If you're thinking plug changes are easy, you have to know this is a 2004 Ford F150 with a Triton V8 engine. So what, you might ask? Well, back in the early 2000s, they designed the Triton V8 with a somewhat unique spark plug design. It has 3 valves per cylinder and the plug is centered between them all, but from the top it's recessed into a deep hole with a long narrow nose firmly seated in the head leading to the tip. It's designed to go 100,000 miles before a plug change is necessary, which is great in theory, but when you try to change them ...
What happens is the narrow nose of the plug seizes in the head, to make matters worse any carbon built up on the tip resists any efforts to unscrew it. Adding to the problem is a plug design where the nose was manufactured as a separate piece. Although there are some who have managed to remove these plugs intact, with YouTube videos to prove it, the overwhelming majority of mechanics will break several of the plugs no matter how well they prepare or how careful they are and I was very careful and prepared. As you might guess, a broken plug in the cylinder head in a deeply recessed hole with extremely restricted access from above will really make your day. When you start this job, be ready for and expect broken plugs, and if you're used to working on motorcycle engines, you'll find these plugs almost comically inaccessible.
Ignoring the horror stories I made up my mind to do it. For several days beforehand I ran a fuel treatment designed to remove and soften carbon deposits. Then I went through the list: Mechanical skills? Well equipped toolbox? Shop vacuum and air compressor? Special tool to remove broken plugs? Check. Lots of patience and time? Check.
Without that special tool, a broken plug means you're done, maybe you have to pull the head, who knows, but years ago, after several companies tried to make a tool for the job, one even including some kind of glue, the Lisle Corporation came up with what appears to be the winning design for a Triton engine broken plug removal kit, it's simple, but ingenious. There are several parts to address the multiple ways the plugs can break and I encountered every variation, using everything in the kit and it works exactly as intended. It's a lifesaver and trying to do this job without this kit on your workbench is simply foolish.
There is a Ford tech bulletin with a detailed technique for changing the plugs, there are also multiple techniques online from those who have had repeated success, some even say to use an impact wrench and let 'er rip, which to all of my years of experience seems just plain wrong, but then, I broke plugs during the removal so maybe they're on to something. In fact, the very first plug I tried, in the easiest to access location, broke. I knew right away I was in for a long day. I actually only changed 6 of the 8 plugs. It was already 5PM by that time and the 2 rear cylinders which are the most difficult to access were still left to do. I had broken 3 of the first 6, so I figured I would break at least one if not both of the last two and removing broken plugs in that restricted space was a job for another day. I also learned by this point there are a couple more very specific wrenches I want to have that will make the job on those last two a bit easier.
The OEM problem was finally corrected by Ford with engines manufactured after October of 2007 so a lot of 2008 Fords are affected. They changed over to a new plug design and if you're buying plugs, make sure you buy the newest version. Although this problem existed in 2004 to 2008 Ford engines, which is a little while back, they sold huge numbers of Triton V8s in F150s and other models, too, and a great many, just like mine, are still in daily use. If you're thinking of buying a used one, check to see if the plugs have been changed and if not, offer less because if you're not up to doing this job yourself, the dealer will make you pay dearly, I've heard upwards of $1000, ... for a plug change! Your average mechanic won't want to touch it. It's a great example of saving a lot by doing it yourself.
Having the extra space in the garage was a confidence builder for a job like this, it's not something I would want to do outside, though you certainly can. This also isn't something you want to tackle if you haven't done a bit of automotive work before and are reasonably comfortable around tools, it would be easy to put your truck out of commission, requiring a tow to the dealer and a lot of money to get it fixed.
Overall, the newly opened space in the garage has proven its worth already and there are a lot of jobs still to come. It was satisfying to do as much as I did and when I get those last two plugs out, I'll feel even better.
Meehawl says
Looks to be an example of design teams that have successfully avoided wielding tools or skinning knuckles in a full spanner combat environment and due to this mechanical imbalance in their training, have unleashed the darkest aspects of an engineers thought process.
Paul Crowe says
Engineers that design engines and components like these should be required to battle the beast face to face, especially if one of their designs has become a service issue. Once they experience actual hand on wrench combat, they may have a new appreciation for what happens after their creation leaves the showroom.
Justin Belshe says
Ohhhhhhh… FORD!
I inherited my dad’s 1995 F-150, I call it Ol’ Frod. It suffered some from his mechanical negligence, but being an old Ford truck, it just keeps going. It’s a 2WD single cab LWB, 5.0 liter V8 with 4R70W automatic transmission. XLT trim package, so there are a lot of luxury features that no longer work.
The transmission has developed a pronounced stutter, and since Dad never bothered to change the fluid, I don’t dare change it now.
There’s an air injection smog port at the back of each cylinder head, and the pipe that connects the two has rusted out and is the source of a rather pungent exhaust leak. It’s very difficult to access, because the bolts are right up against the firewall, so replacing the pipe can be an ordeal. Smog port plugs are inexpensive to purchase, but almost impossible to install because the carbon build-up in the ports is so difficult to remove because there isn’t room to get a tap in there.
One particularly egregious engineering error was the plastic material chosen for the numerous vacuum lines! The stuff has become extremely brittle, and crumbles to the touch. Vacuum leaks cause a whole host of problems, so I recently ordered some Teflon tubing to replace it.
The passenger window no longer rolls down. The driver’s window rolls down, but doesn’t want to roll back up because, again, Ford chose an inferior plastic material for the rollers inside the electric motor. Accessing the bolts that hold the motor inside the door requires drilling holes through the steel inner skin of the door.
But changing the spark plugs? An hour’s work!
😉
Peter says
genius idea those spark plugs.
NOT!
Nortley says
Sometimes the factory does fix things. My BMW GSPD had a folding oil filter so it could be changed without removing the engine guards.
Paul Crowe says
Folding oil filters? Really? Interesting.
Alex Zemlin says
I firmly believe that anyone that is going to design/engineer anything for a living, needs to spend six months to a year in that industry, fixing mistakes made by the previous generation of designers/engineers.
Your spark plug story is a stellar example.
Robert says
The factory gets it wrong a lot. No surprise there.
I worked for BMW for 25 years and saw more than my share of horrors.
Anyway, ease of service is waaaaay down on the list of priorities for the manufacturer.
Most owners don’t work on their own vehicles, so they likely don’t much care.
The problems get left for the intrepid DIY’ers and mechanics to work out.
Matt Higgins says
MyI neighbor has two vans he uses for his plumbing business, one a Ford, the other a Chevy. They both have tons of miles on them and one fouls plugs once a month or so. He has become quite good at changing spark plugs it the offender, having to loosen up the motor mount on that side so he can jack up the engine. Then comes the hard part!!!
Adrian says
Is good to have you back
steve davies says
I feel your pain. My son in law has a 2004 F150 with the 5.4 with those horrible spark plugs. Took me 2 days to change the plugs because 6 of them needed that extraction tool.
I have been engineering for 30 years and I suspect it was a management/finance decision that caused the problem, not the engineers. Still fighting these problems to this day…
Mike says
So good to see the Kneeslider again! I was a daily, but silent, visitor for years and drifted away when you slowed down and changed direction.
I got to wrestle with the bastard spawn of ‘creative’ engineering in the form of an ex-girlfriends Renault 5 hatch. We were impoverished students and I was all that stood in the way of us walking. Struggled with a number of stupid design fails that must have come from the minds of people unfamiliar with wrench application. One was a split in the firewall where the clutch cable breached it. At 50k KM it pulled right through as the firewall as it was completely un-reinforced at that point. Bodged a fix for a week by wedging the prongs of a number of barbecue forks between the cable flange and the firewall.
Another was that the cooling system couldn’t be bled of air completely without jacking the front end up . Given that it was a leaky system that frequently overheated this required a trip to a nearby slope to complete a coolant refresh.
Your spark plugs may be an even dumber fail though given the resources of the operation that came up with them. They look like a clever solution looking for a problem!