Damn spark plug hole...

[mix4]

Ok first off, when I redid my head gasket set we stripped the first spark plug hole on the left side. We got a kit from the auto store that came with a threading tool and a 'sleeve' that goes on the plug to make it a bigger thread. Well about two weeks ago the sleeve gave out and the spark plug shot out of the hole. I had 2 other sleeves in my trunk so I just used a new one. Yesterday it happened again, this time I lost the plug. Bought a new one and some intense heat adhesive to make the sleeve stay this time. Problem is, the shit won't screw in now, I can't really get in there to see if the thread on the head is shot or what it could be. Someone told me I could JB Weld the plug in... this doesn't sound like a very smart idea to me. Another option I was told was to get a plug with bigger thread, how do I know what to get? Right now I'm driving the thing around on 3 plugs, I have to, work is far enough away where there's no way I'm walking. Any ideas?

Oh yeah, the car is a 1989 Accord LX (carbed)

[AccordEpicenter]

lol i bet the jb weld trick will work for that, seriously. Lets see, instead of using a sleeve i would have heli coiled it from the get go... Aluminum threads suckkk!!! !

[mix4]

lol i bet the jb weld trick will work for that, seriously. Lets see, instead of using a sleeve i would have heli coiled it from the get go... Aluminum threads suckkk!!! !

So should I just put some on the plug threads, without the sleeve, and just shove the plug in the hole? How much do I use? Is that shit really that strong it'll hold it?

[skycam_313]

you put jb weld and youll never get that plug out again.
these will work wayyy better than the other crap
try this


*edit plus heli coils have a chance of coming out

[mix4]

you put jb weld and youll never get that plug out again.
these will work wayyy better than the other crap
try this
*edit plus heli coils have a chance of coming out

Well its a brand new plug so I'm expecting it to last as long as the car does until it finally shits itself.

[mix4]

Do you know which Heli Coil kit I need to get?

[Oldblueaccord]

Before you go for broke on the JB weld you might want to atleast get a bolt and try threading it down the hole and clean/make new threads. I think spark plug threads are 14mm. Make sure the piston is DOWN in the bore before you go poking around in there as well with anything to long.

Really, and I think you know this, the head has to come off to be fixed properly.


wp

[mix4]

I have a 14mm thread tool but I can't get enough leverage on it to make it start threading. I'd really rather not have to take the head off, I just redid the head set its brand new. The plug will screw in tight part way but then when I wiggle it it comes right out. I'm thinking the threads are pretty fucked. The weird part is the spark plug won't even screw in without the sleeve on it, I'd think it would kind of screw in loosely at least since its smaller thread...

[Ichiban]

I do believe that spark plug threads are different than the typical ISO metric thread form. Also, since it was drilled and tapped oversize to accept the sleeve, the hole is going to be way oversize. Did you expand the top knurled portion of the sleeve with the taper attachment that comes with the kit? This step is essential, as it forces the knurls into the head material and prevents the sleeve from coming out again. The local engine builder also coats the OD of the sleeve in high heat permanent loctite as an added precaution. Assuming you still have the special tap for the sleeve kit, you should chase the threads in the head, install another sleeve and make sure you follow the instructions EXACTLY. I've never seen one of these inserts fail when installed properly.

[mix4]

It didn't come with any kind of taper attachment, just the thread tool and a bunch of different sized sleeves. I tried chasing the threads but the tool won't thread in it pretty much just sits there and spins, same with what I'm guessing the plug is doing.

[Ichiban]

In this case, you are probably going to have to find a machinist who will make an even larger sleeve, tap the head again, and insert the sleeve with an acceptable method of securing it so it doesn't unthread again. Or you will replace your head. Any other fix is temporary and likely to fail.

[mix4]

Cool. Sure glad I planted that money tree in the back.

[Blazin]

shoulda used a thread chaser when it first striped, woulda solved it all.

[Oldblueaccord]

Cool. Sure glad I planted that money tree in the back.

Figure out what size that insert is OD and we will go from there. Or send us a link to the style. you' ll need to tap it to the insert size or what ever heil coil you use. Heil coil use there own thread a regular tap is not correct . Im guessng the insert is like a 16 mm or larger.

Reason I said use a bolt is it is easier to get leverage in a bad spot,there cheap, and easy to find. It's a hack but it will prolly work in Aluminium. The tap those sizes can be pricey.


wp
https://www.mactools.com/portal/site...extfmt=default

these are 90$ but i like that style.
EDIT

[mix4]

shoulda used a thread chaser when it first striped, woulda solved it all.

Uh, I did, thats how I got the sleeve in...

[Ichiban]

A special self-drilling heli-coil tap that is supplied (usually) with the kit is used. I'm unsure of the thread on the outside of the sleeve, whether it is a standard thread form or what. I know that the taps for the actual "wire" heli coils are their own thing, as the tread pitch is same as the fastener used, not what would usually be in a hole of that size. A thread chaser will not help once the threads are stripped, as there is not enough material left to manipulate. They are for threads that have minor damage but are relatively intact. You can make a cheezy thread chaser by grinding slots axially down the length of a bolt, or cutting slots in a nut for external threads (you can also invert a castellated nut, has worked for me before)

Edit: I'm to understand that the threads in head that the sleeve engages are stripped?

[mix4]

The plug, with the sleeve on it, screws in and gets tight part way, but then if I wiggle it, it just comes out. So I put JB Weld on the sleeve and turned it until it was tight and left it like that. I guess we'll see if it holds tomorrow, gonna let it sit overnight like that.

[Oldblueaccord]

"This could really pull your acorns out of the fire if you (or one of your techs) is a little overzealous installing plugs"


That 's off that Mac site funny shit.


Good Luck with the JB weld


wp

[AccordEpicenter]

i actually think it might work. Ive seen the threaded inserts and soo far helicoils have been my fav but thats just me... If you need to tap it out just coat the tap in grease so all the metal bits stick to it and go slow. Did i mention how much i hate aluminum threads?

[Oldblueaccord]

Update?



















wp

[88Accord-DX]

Update?
wp

Shhh, we're waiting on the JB weld to cure.

[mix4]

Well I just got back from work. The JBW seemed like it dried nice and strong, so I tightened the spark plug into the sleeve, and the fucking sleeve came out. So, I'm thinking about filling the hole with JBW, letting it dry and then using my thread tool to put threads in the JBW. Its my last option before it starts getting expensive.

[AccordEpicenter]

ehh it must be pretty messed up then, jbw doesnt like to be threaded. You might need to pull the head. How many miles does the engine have? Good condition or ?

[lostforawhile]

you should have sent the head to me i might have been able to save it. with whats happened to it now,i doubt anyone can save it. if you had a caliper or a set of telescoping gauges you could have measured the hole size. you still might be able to helicoil it. find out what size drill bit is required for the helicoil tap,for the 14 mm spart plug hole. see if that size drill bit will fit through the hole, if it doesn't,you can still drill it for a helicoil. i know it's getting expensive,but thats why to helicoil in the first place. and a helicoil installed properly will not back out. you are probably going to have to pull the head,i hate to say it,but you are going to get metal in the cyl. if you don't. you can probably use all your gaskets over,except for the head gasket.

[3rdgenhatchDX]

Buy a new head...

If you would have had the head decked at a shop when you did the gasket you could have had them rethread and fix the hole, i'm guessing you didn't deck it?