Cross Threaded Spark Plug Repair?

Have a 2009 4.0 with 130k on the clock. This last weekend I went to replace my spark plugs and one of them unscrewed about 2 turns and then locked up and wouldn't budge. I was able to thread it back in tight and leave that 1 plug alone for now, but this will need to be addressed eventually.

I have always done my own plugs and am very careful not to crossthread them. I dont believe there is any way i messed this plug up on the last change, but anything is possible. Im not even sure its in fact cross threaded but it sure feels like if i continue to unscrew it that its gonna snap or strip.

I obviously want to be either at a shop or prepared for the repair before attempting to pull the plug, that way i can avoid a tow just incase.

My question, has anyone done a helicoil repair before and if so, anything about this motor that can help me out? Should i find a shop to do the work or try myself? Ive repaired threads before, but never used an insert or helicoil type repair and never done spark plug repair. Any tips or suggestions?

Thanks

 

is it throwing a code or you are just doing pm?

if it's still performing fine I'd leave it be

 

Maybe it’s just the plug threads. Try a different plug to rule that out.

 

You may not be dead-in-the water yet. Back the plug out a little bit...maybe half way before it binds and hit it with penetrating oil and let it sit. Wait for a half hour, screw it back in lightly, then back it out to where it starts binding...screw it back in a little and hit it with another short of oil...repeat as necessary. This has worked for me in the past. If the plug eventually comes out, look at threads...if there is a whack of aluminum in them...yup its heli-coil time.
NOTE: Do this on a COLD engine only...in fact you should never-ever take a plug out of an ALUMINUM head while HOT.

If it in fact strips...a decent mechanic can install a heli-coil without pulling the head (had it done years ago on an old Corona I had).
Hope it goes fine for ya.
Cheers, Jeff

 

You could try this;
1. Warm up the engine, the shut it down.
2. Pull the coil out, and shoot some Seafoam deep creep into the plug hole.
3. Then work the plug back and forth (as far out as you can get it until you feel resistance).
4. Next shoot some more deep creep down the hole, close the hood and let it sit over night.
5. Next morning, install the coil, fire the engine and warm it up, shut if OFF and try to remove the plug.
6. If it comes out, your Dun, if not you may have to end up using one of these, a shouldered threaded insert, I would not trust a helicoil for a long term fix.

 

Preventative. No codes

5 plugs i replaced. The one thats stuck is the old plug that wont come out. So thats where im stuck

I tried penetrating oil but only once and gave up quickly. Ill do this on a day i have time to take it slow. I was just terrified of it breaking inside the head and having no vehicle. So i want to do this when im in a safe place the vehicle can stay in case something goes wrong

 

I understand your concern for sure, but I would doubt you'd break the plug...the threads in the head will let go first. Just take your time with it...could take all afternoon. Remember...COLD motor.
Good luck and report back.
Cheers, Jeff

 

Smart choice. It is possible to break the plug off. I've never done it myself, but I've seen it done. Then you have a huge problem. The metal between the shoulder and the threads is not very thick.

 

Ill update this once i give it a try. Probably give it a little while since i have a week long trip planned in 2 weeks so i definitely dont wanna be SOL before that

 

I've used one of the shouldered threaded inserts (Timesert) as mentioned above in a Yamaha R1 aluminum head with great success and that is a 12:1 compression motor that revs to 10k. Just try to get as much of the metal shavings as possible out of the cylinder before firing it up as they can damage your valve seats.

 

soak it in penetrating oil let it sit overnight, try again

 

^^^^^^^THIS ^^^^^^^^ and move the plug back and forth to help the oil get down where it needs to go. You may just have a lot of carbon built up on that plug. Do this with the engine cold and take your time.

 

Man...... mangled frame now stuck plug. Good luck!

 

Man its its been an adventure with this thing but im finally back to normal when this happened. Frame is straight, rear axle has been replaced, third regeared and added a locker. So some good has come of the repairs. and a ton of other replacement parts too but its been driving like a dream lately. Just this one plug which really isnt the end of the world. I figure worst case if penetrating oil and patience doesnt work, i go to a shop and have them rip it out and rethread it. No big deal. Just a bummer

 

Hopefully it will free itself, but a machine shop should definitely get it done. Enjoy that locker and have a safe trip! Deal with that bitch when you get back.

 

I have the same issue. # 5 plug is stuck because the spark plug tube is blocking the socket from going all the way down. I attached a picture, but I will try to take a better one soon. I have changed my plugs a few times and haven't had an issue. Any ideas?

 

How is the spark plug tube blocking it?? Are you using an impact socket? Did you use anti-seize on the threads when you installed them last?

 

Another reason that I hate aluminum... Strips way too easy. I wish you luck!!!

 

If you look down the tube you can see it is uneven. I have used every type of socket that you can find. It will not go past the second half of the tube. I can't get the socket all the way down to the plug. I hope this makes sense

 

I'm looking at it on my phone, but it looks to me like there's a rubber O ring jammed down in there.