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Spark Plug Removal

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Snojetter View Drop Down
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    Posted: 24 Aug. 2018 at 3:43am
Hi folks - new guy here.  The topic title might lead you to believe I've never held a wrench before...but I've pulled a plug or two in my time. Anyway, I've got a '46 CJ-2A that's been sitting in dry storage for quite some time - 5 or 6 years I'd say.  I went to it the other day just to tinker.  I noticed there was some crud build up around the plug, so I blew off the junk and decided to remove the plugs and see what they looked like.  I loosened #1 enough that I could spin it by hand...but I soon noticed that it wasn't actually un-threading.  It was just spinning in the head.  The ceramic is not loose from the body (which I've seen happen before).  This plug just spins without being able to remove it.

I find it hard to believe that the threads are stripped, but even if the threads are buggered, I would still think it would climb up and out on whatever threads are left.  If I try to exert "up" pressure and spin, it still won't come out.  I can turn it left or right and it just spins - no tightening, no loosening.  What could be holding this thing in place?  If the threads are shot, it should just pull out.  If there's some bit of thread left, it should walk up and out with some level of effort.

I assume I'll have to pull the head to get this plug out.  I'm just curious is anybody has ever experienced this before?  It's a new one to me.
Kyle Sands <>< Brandon, MN
1946 CJ-2a
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Unkamonkey View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Unkamonkey Quote  Post ReplyReply Direct Link To This Post Posted: 24 Aug. 2018 at 5:40am
Very interesting, I have never heard of that. I had a '64 VW that the number 3 spark plug would on occasion decide to send one off into space. you probably should check into Helicoills.
uncamonkey
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Post Options Post Options   Thanks (0) Thanks(0)   Quote cpt logger Quote  Post ReplyReply Direct Link To This Post Posted: 24 Aug. 2018 at 5:52pm
I have seen a few where someone installed a spark plug that was the wrong length. In other words, the threaded section was too long. The treads sticking into the combustion chamber collected a carbon coating. When the mechanic tried to remove the plug it would turn about 1/4 turn, but the carbon would not allow the plug to come out. The mechanic then forced the issue & stripped the threads.

I suspect that this may be your problem. If so, your best bet is to pull the head. Then, after removing the spark plug, Heli-Coil that spark plug hole . 

I would never admit this out loud, but I may have done that & instead of fixing it right then, I may have just driven the rig until the spark plug blew out of the aluminum head.Embarrassed I do not recommend that approach. However, I found another Heli-coil like repair kit & was able to fix the head without pulling it. Thumbs Up 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ol' Unreliable Quote  Post ReplyReply Direct Link To This Post Posted: 25 Aug. 2018 at 2:53am
Welcome to the page, Snojetter!
There's a reason it's called Ol' Unreliable
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Snojetter Quote  Post ReplyReply Direct Link To This Post Posted: 28 Aug. 2018 at 3:07am
That sounds like a plausible explanation.  I suppose I'll find out when I pull the head.  If I did strip the threads, they were pretty weak.  I didn't put much torque on the wrench except to break it loose.  After that initial force to get it turning, I didn't meet any unexpected resistance - that initial turn to crack the plug loose must have stripped the threads.

I've had this Jeep for almost 25 years and the plugs are ones I installed back in the 90's - Champion J8C's.  I thought those were the correct size...but who knows.  I was a foolish teenager back then.
Kyle Sands <>< Brandon, MN
1946 CJ-2a
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Post Options Post Options   Thanks (0) Thanks(0)   Quote JeepFever Quote  Post ReplyReply Direct Link To This Post Posted: 28 Aug. 2018 at 5:20am
I did not reply on original question,  because I have no answers.  Confused
 
Welcome to forum,  hopefully a simple fix,   . . .  but seems scary.  Smile
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 48willys Quote  Post ReplyReply Direct Link To This Post Posted: 28 Aug. 2018 at 12:56pm
It does seem odd, a j8c should be short enough to not get buildup on it. I have had them break off at the base and the porcelain holds it together, bad thing about that is the porcelain tip can break off and drop into the cylinder.
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1948 chevy 3800 thriftmaster
1946-50's cj2a-3a farm jeep
1993 yj, aka the yj7
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ol' Unreliable Quote  Post ReplyReply Direct Link To This Post Posted: 30 Aug. 2018 at 5:18am
A J8C is the correct Champion plug. 
There's a reason it's called Ol' Unreliable
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Oilleaker1 Quote  Post ReplyReply Direct Link To This Post Posted: 02 Sep. 2018 at 11:48am
Cast iron is much softer than a steel spark plug, so your head most likely suffered. I think there is a kit to install a slug or wider/better fix than a heli coil. I'd do some more research before you jump. Another head would also be a option. Maybe it's time to upgrade to a Supersonic , higher compression head? 10 more HP would sure be a bunch in a old Jeep. Oilly
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Greaser007 Quote  Post ReplyReply Direct Link To This Post Posted: 22 Sep. 2018 at 2:16am
So then, once the head is removed, how is the plug extracted without breaking the head ?

Is it safe to break out the porcelain and blow the plug out with a torch ?

Then chase the threads and Heli-Coil if necessary ?

I haven't been faced with this dilemma yet ?

Just the other day, I was reading an ad for an L134 which said the Plugs needed to be Extracted !   And it was a coastal engine. Hmm could be a similar dilemma.

Edited by Greaser007 - 22 Sep. 2018 at 2:22am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote DonH Quote  Post ReplyReply Direct Link To This Post Posted: 22 Sep. 2018 at 5:47am
This has not happened to me. That said, you will have to remove the head and see what it looks like inside. I am thinking that you might be able to apply enough pressure to the plug from the inside to allow it to be turned out on whatever threads remain. Beyond that removing the porcelain and drilling would be my next choice with the goal of limiting the damage to the plug itself, the same removing a broken stud  or bolt.

Good luck to you,

DonH
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 3A Steve Quote  Post ReplyReply Direct Link To This Post Posted: 20 Oct. 2018 at 10:24pm
Bought a rotted 3A when the thought hit me that I needed to repeat years ago experiences with a 47 2A. Ended up throwing most things away and selling anything useful. The engine appeared to be seized (it wasn't and someone who bought it for the crank found it better than the engine they had) and there was one spark plug I couldn't get out. It was sitting higher than the others. Have since been told that people used to do that when their engines were burning oil and they would put an extra bolt/nut in to get the plug to sit higher. Anyway, took it to a machine shop that does engine rebuilds for Kaiser (at least that is what they said... and they did have a long row of 134's on the shop floor). Cost $140 to have the plug pulled and the head resurfaced. The rebuilt head is one of the last parts left, just in case the current 3A needs one in the future.
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