Thread insert for blow spark plug 6.8L V10 Triton

[coloradoclimber]

tldr; 2001 F250 SD Triton 6.8L V10, blow spark plug, identify the heads, cut the seat, ream, tap, and insert all 10 cylinders, videos and pictures http://www.techspin.info/archives/category/f250

Long Version:

I recently purchased a used 2001 F250 SD XLT Quad Cab long bed FWD. It has the Triton 6.8L V10 with the aluminum heads. I did my research before purchasing and knew about the possibility of blown spark plugs and torn out spark plug threads in the heads in the V10.

The guy I bought the truck from is a mechanic for the county and he had changed out the fluids, generally cleaned it up, and ... changed out the spark plugs. I asked about the plugs, he admitted to changing them out. Everything looked good, the truck was running fine, the new plugs should be good for another 100k, more than I would ever drive it, sounds great, done and done. I bought it.

Three, that's right 3, trips later I was pulling away from a stop sign, I heard a pop, and it sounded like there was a Harley stuck up under my hood. At first I thought maybe I'd dropped an exhaust manifold (another notorious problem with the Triton). But a quick lift of the hood and it was obvious I had a blown spark plug .

I did the internet search thing, looked at prices to get it fixed by a mechanic, about choked on that, and decided I'd figure out how to fix it myself.

What I didn't find was a lot of information on how to actually fix it. Eventually I decided to put in steel inserts and ended up using a Timesert kit and inserts. Since I didn't find as much information as I would have liked when I was trying to figure out what to do I wrote down some of the steps, took some pictures and videos, and posted them on my blog and youtube. Hopefully these vids will help the next freaked out Triton owner get his or her truck back on the road for a reasonable price.

I inserted all 10 cylinders. Everything went reasonably smoothly. I've got about a thousand miles on since getting it back on the road. So far everything is looking good. We'll see how it turns out down the road.

Check it out at

http://www.techspin.info/archives/category/f250

and

https://www.youtube.com/playlist?list=PLJiS4tBInO3zNl4FqRzTRtHnqUEZ3t2-Z

 

[smokey]

Nice write up.

 

[5.0Flareside]

Key thing with those heads is the torque on the spark plugs.. If torqued correctly you don't have issues typically

 

[coloradoclimber]

Hey Flareside,

Not sure I'm drinking that coolaid. So let's say you have the thread profile, you can get that from the manufacturer, or let's say the manufacturer has that. You're gonna need that so you can calculate the thread cross section so you can calculate the shear strength.

You probably also need the material properties, any alloys, heat treating processes, need theses to get the material strength.

Gonna need the spark plug thread to well friction. Any oils, dirt, cutting lube, cleaner, etc. That's for sure gonna affect the torque to axial shear.

You're gonna need all of this, plus some math, to figure out the proper torque to tighten the plugs.

Seems like a lot to ask.

What's that you say, just use the manufacturers recommended torque. They have all that stuff, the thread profile, material properties, controlled manufacturing environment. Sure, maybe, but do you? I sure don't. Who knows what the thread-in friction is going to be on my 10 year old truck with 100k miles on it. And I wonder about the thread profile, does it really match the ideal profile calculated by the manufacturer? Even after the production tap has worn after it's 500th spark plug hole?

I don't know. Having the manufacturers recommended torque seems like a good piece of information, but I'm not buying the, "It's all been calculated by the manufacturer, use that torque" line.

Seems like a reasonable starting point but I'm inclined to believe using the manufacturers torque on a 10 year old truck is just as likely to lead to thread shear as just tightening the plugs by feel. But I'm old school. I sure could be wrong.

Edit: I just re-read your post, "If torqued correctly you don't have issues typically". Well, I guess that makes sense, if torqued correctly you wont over torque them, and you wont have a problem. How do you get "torqued correctly"? I assumed you meant use the manufacturers recommended torque, but you didn't actually say that. So I just try to torque my plugs correctly by hand. Maybe that's what you meant.

 

[coloradoclimber]

Thanks Smokey.

I know the write up could use some clean up to remove some of the redundancy and rambling. But I knew that if I didn't just post something there was a good chance I'd never post anything. Now I got it out there and maybe over time I can clean it up.

 

[5.0Flareside]

There is a torque spec from ford for em. I don't know it off top of head but tons of lightning guys I know still running 4 thread heads and 16#'s of boost and no issues cause torque spec..

But either way great write-up

 

[blacksnapon]

What I've seen, operating conditions, weather can influence it as well. The steel body of the plug, and the aluminum head expand and contract at different rates. The difference in metals can make corrosion (the statue of liberty suffered the same fate with the copper skin and iron skeleton). Add this to moisture/coolant/condensation getting into the plug hole, you have corrosion in the making. Some might blow out plugs, some may never. Proper torque may actually be too much for damaged threads, others will be just fine. I tell all of my customers, the first plug change needs to happen at 25-30k miles instead of 100k. Use anti sieze, and you might escape any issues.

 

[95F350XL]

KD makes an awesome kit that we use at work. They did change the tap design for the nutsert and the head is too big now and with a socket it wont fit down the spark plug well. We just use the old one still. As snap on said, lots make it happen, usually from lack of maint and plugs put in too loose.

 

[coloradoclimber]

Update Jan 2013: I just returned from a 1300 mile trip through the Colorado, Utah, and Wyoming Rocky Mountains. Uphill grades for 4 hours straight, downhill for 40 miles at 6 and 7 percent. I could do 70, 75, 80 mph, uphill on 6% grades for 20+ miles without slowing down. 40 miles of downhill at 6 and 7% in 3rd gear compression braking for nearly an hour. No problems detected. Engine is still running like a champ with no observed issues with any of the 10 inserts. Truck was lightly loaded, just some camping gear in the back and 4 adults and stuff in the cab. So far so good. We'll see how it goes next summer pulling a trailer around the same path.

 

[95F350XL]

How come you had to do 10 inserts?

 

[coloradoclimber]

95F350XL, I didn't really have to do all 10 if I only wanted to fix the immediate problem, only one cylinder had actually blown.

But the guy I bought the truck from had recently replaced all 10 spark plugs and if my reasoning is correct, that changing the plugs in the original 4 thread design, leads to the thread failure, I could have expected more plugs to eventually blow.

I had the truck broke down to fix one plug, I expected that sooner or later more would blow, I didn't really want to be broke down again and again, so I just decided to go for it. Do all 10 and get it done. If I screwed it up, well it'd have to go to a mechanic anyhow, so what the hell, give it shot, get em all done and done.

It was a little more expensive, the inserts are about $12 each so $12 for 1 or $120 for 10. The time spent wasn't that much worse. The first plug took the longest and each one after that got quicker and quicker. Obviously it took me longer but maybe only a couple extra days, and that's because I'm slow and careful. A trained mech could probably do all 10 in less than a day, start to finish.

The risk is that each time you do a cylinder you run the chance of messing up. So you could say I multiplied my chances of ruining the heads by 10. But it was worth the risk to me.

I did not trust the other plugs, I did not want to be broke down again, I did not want to do this job again. I wanted to be done, one way or another. So I went for it. And so far it seems to be holding. Time will tell.

 

[coloradoclimber]

uh, and the update above should have read, Jan 2014. Gettin' old, just like my truck...