Stripped Spark Plug thread, cylinder #5

I got a code the other day that said my #5 cylinder was mis-firing, a few days before we had changed all the spark plugs, and after I got the code we changed the ignition wires. Before we even got the code, the car had started shaking in idle and had a rough take off. We replaced the fuel filter, and when that didn't stop the shaking, we re-checked the spark plugs and noticed the 5th cylinder's spark plug would not tighten, still causing it to misfire.
Point to this post being: I called a local shop and asked for an estimate on how much it would cost to repair the thread, they in return tell me $40, maybe more if they have to order a kit for it. My step-dad "knows" of a guy that will do it and charge me $50, but I heard it can be dangerous to attempt to fix it over the fender because of the metal shavings, and the chance this guy is crazy and screws something up. Is $40 a realistic estimate? I just don't want to take it in and find out I have a $500 bill.

I'm not sure what the shop means by "a kit." I suspect they are referring to a helical coil insert. If the threads are so stripped that the plug won't tighten, and the problem is not with the threads on the spark plug exclusively, then they will need to install an insert.

I don't know how much extra to expect to pay for the installation of an insert, but I don't think it would be more than a $100 adder. Maybe someone that's had this type work performed will be able to provide a better estimate. Fortunately, cylinder #5 is the center plug on the front bank, so it's easy to get to.

As you've eluded to, a shop will be insured so if the work is not done correctly and shavings obviously lead to catastrophic failure, they have insurance to minimize the expense to you.

-Rod

You need a tool like this http://www.autopart.com/tools/toolsmain/tool/T_98147.htm Helicoils aren't for tapered plugs. You need the valves closed. Use a vacuum cleaner with some hose in it and vacuum the hole. Way2old has some police cars with 70,000 on after this job. Greese the tool it collects shavings. If your Dad's friend knows he doing go for it. Way2olds mechanics unplug the camshaft position sensor and blows the chips. Use red permatex on the insert and anti seeze on the plug. If real close quarters Advance Auto sells a set with an extension plug so no socket is required.

Thanks for all the input! I watched a few videos on the demonstrations of the tool to fix it and it doesn't look that hard, so it's a 50/50 of me being annoyed and worried about spending a outrageous sum of money or potentially screwing up my engine. The guy at the shop reassured me that they have done it a million times, and that they have the tool for it. I'm just hoping that they won't have to order a helicoil and that they will be able to fix it.

Another question I had is would it being off just a little still cause it to misfire? Could something be wrong with the ignition coil pack?
I just don't know which would be the best route to take, but I feel better with someone that is insured, as opposed to some guy across the street.

If either one screws up you have to pull the head and go to a machine shop.
If he's fixing blown out plugs I assume he can pull a head.
Always fix known problems and then remove codes and rescan. Don't let either of them install a helicoil insist on an insert. For the price of the tool it isn't that expensive.

What is the difference between what that kit contains versus a helical coil insert versus a Heli-Coil? We use helical coil inserts at work that have a removeable tang as well as tangless. Helical coil inserts are also available in a locking insert which would seem the best route for a spark plug hole repair. Since the spark plug receives its ground through the head, it doesn't seem like the best idea to install a potentially insulating (no pun intended) thread locking compound between the insert and the head.

-Rod

The manufacturer of the kit gives instructions with the insert which states to use red permatex. These inserts are thicker and if you look at the tool it peens the top for tapered plugs. It also locks the insert in place the anti seeze allows the plug to be removed without pulling the insert. My heli coil kit says don't use tapered plugs with them. When removing a plug with a heli coil they tend to come out with the plug if he doesn't have a tool its back to the shop. Even if an insert comes out I've taken them off of the plug and reused them.
Any compound will stay in certain areas preventing leaking it will wipe off certain areas so the plug is grounded.
I have a time cert kit and the tap is the same part number. A friend with a shop uses these inserts and the engines have been out over 1 year with no problems. Matco sells the time cert kit so a lot of mechanics use them also.
Ford also says don't use helicoils in Triton engines. They even specify a specify an aluminum alloy for the insert. They sell them on ebay with $600.00 kits. A company will even come to your house if you have a garage for a fee but cheaper than going to the Ford garage. The companies have a video and instructions on the web site. Ford changed from a 1/2 thread plug to a full thread plug because of all the inserts on these engines. Ford dealers get around $1200 to $2000 for the job.

Interesting, I didn't realize the issue with the tapered plugs.

I had heard about the issues with the Triton, at least on the V-10 and their 5.4L SC Lightning.

-Rod

We purchase our repair kits from a local aftermarket parts house. They also come with a staking tool that "sets" the insert along with screwing it into thwe threads. Also use grease on the drill bit and have it turning aaaaas slowly as possible. The grease will help remove the shavings. Good luck.

A company will even come to your house if you have a garage for a fee but cheaper than going to the Ford garage.

I have a 4.6 in a Supercrew where the #7 cylinder blew the plug out and it's stripped. Pep Boys says I have to get it to a Ford Dealer - who is the company that will come to your house? I'd rather not spend money at the dealer if I don't have to - the engine in my Supercrew is out of a 2002 Grand Marquis.

Any specifics will be appreciated. Thanks Prof

A company will even come to your house if you have a garage for a fee but cheaper than going to the Ford garage.

I have a 4.6 in a Supercrew where the #7 cylinder blew the plug out and it's stripped. Pep Boys says I have to get it to a Ford Dealer - who is the company that will come to your house? I'd rather not spend money at the dealer if I don't have to - the engine in my Supercrew is out of a 2002 Grand Marquis.

Any specifics will be appreciated. Thanks Prof

Doing a bit more research the Timesert kit 5553 looks to be the solution, however is there someone out there that does the work for a fee? Prof

Does anyone know what happened to resolve this case?

Haven't heard. It is also close to a year old.

before tapping the threads and putting in a helicoil or timesert try a thread chaser. I did this and put vaseline on the threads to catch metal shavings and I rethreaded stripped out plugs.

It's been nearly 2 years since the original post, so I suspect he's repaired the issue by now (sure is nice when posters follow-up with their solutions!). That being said, since in this case the spark plug would not tighten up, chasing the little existing thread material is not going to lead to a safe and secure solution.

-Rod