Spark Plug Thread Replacement

[taxx]

Has anyone had any luck using the inserts (which ones) to create new threads for a plug or two? How well do they hold up if you run it hard?

 

[mrboyle]

The only way to properly repair stripped spark plug threads is to remove the head and either replace it (best) or have the holes repaired by a machine shop (not my favorite, but will work). There is no way to do properly with the heads still on the vehicle.

 

[taxx]

That is what I was affraid of!

 

[taxx]

Well the over priced mechanics at Ford were able to clean up and chase the threads. I couldn't find anyone cheaper to do it. They claim that it isn't gaurenteed, but I am sure it is pretty solid. They said to replace the head they have to pull the engine? Anyone had any luck changing the head on a SOHC? Do you really have to pull the engine? I think it will hold for a year or two till I get my 302 built up.

 

[midnight2001se]

Well the over priced mechanics at Ford were able to clean up and chase the threads. I couldn't find anyone cheaper to do it. They claim that it isn't gaurenteed, but I am sure it is pretty solid. They said to replace the head they have to pull the engine? Anyone had any luck changing the head on a SOHC? Do you really have to pull the engine? I think it will hold for a year or two till I get my 302 built up.

Can anyone answer this question? I have the same problem and was wondering if you need to pull the engine to replace the head? I have a 2001 Sport with a SOHC 4.0.

Thanks

 

[Glacier991]

I'd not be dissing FORD mechanics...as a general rule they are some of the better trained dealership guys out there. THEY do not set shop rates nor book times. Some of the bestest and brightest guys I've known in the auto world were FORD mechanics.

 

[midnight2001se]

I'd not be dissing FORD mechanics...as a general rule they are some of the better trained dealership guys out there. THEY do not set shop rates nor book times. Some of the bestest and brightest guys I've known in the auto world were FORD mechanics.

do you know if the engine needs to be pulled or not?

 

[Eneurb]

I'd not be dissing FORD mechanics...as a general rule they are some of the better trained dealership guys out there. THEY do not set shop rates nor book times. Some of the bestest and brightest guys I've known in the auto world were FORD mechanics.

Thank you!! It's nice to not be labeled as a theif because I am a dealership mechanic. Oh, and you don't have to remove the engine, but it makes it alot easier if it's the right side head. We use a product from Car-Quest called "Sav-A-Thread" on the infamous 4.6, 5.4 and 6.8 engines for blown out spark plugs. It is a tapered insert that we have had 100% success with, but we also do not guarantee the repair, as it greatly changes heat transfer and expansion rates. We do not remove the heads to install them, but the proper way (Ford's official answer) is to replace the head.

 

[Glacier991]

Eneurb, my pleasure. It's how I feel and what I believe to be the truth. You are a perfect example of what I am saying. Work all day doing auto mechanics and come here and help others with your extensive knowledge after hours. My hat is off to you - AND your fellow FORD mechanics.

ps I once worked for a couple years in a FORD dealership as an apprentice mechanic, in Boulder Colorado - in another lifetime. Even attended some FORD schools during that time.

 

[Opera House]

Just curious, I've heard it said they fill the cylinder with shaving cream on the down stroke to catch the metal particles when retapped. Cranking it over after then blows them out the hole.

 

[ExplorerDMB]

I am guessing it is like a heli-core: you drill out the hole and then run a certain side thread in and then you put a type of "core" that will slide into the bigger threads and give you the old size of the whole and thread pattern. I do believe we have done this before on a few motorhomes we get - but I am not exactly sure. I never thought they were that strong - I've only used them on brake cradles and brackets. My $.02

-Drew

 

[Eneurb]

The insert is nothing like a heli-coil. It is a solid insert, requires no drilling. What comes with the kit is a tap that starts at the size of the original thread, and is tapered to the size of the insert. I cover the tap with grease to pick up the filings, and remove it several times to clean it while tapping the hole, making sure the piston is not at top dead center, as the tap goes nearly an inch into the combustion chamber by the time it is all the way in.