Yeah. It was fun. I thought the exhaust pipe busted open, or something, since that's been steadily rusting away.
Loud sounds. You know you're loud when people in New York City stop and stare.
Anyway, so I cross-threaded my #4 plug on my 22re and used a thread chaser to clean things out a bit. Everything was fine for a month, and it just popped out today on the highway. I'm assuming that it unscrewed itself, since the threads are still there.
So, can anybody give me a heads-up of what I'm going to have to do to fix this thing? Pull the head, and then helicoil it? Thread locker?
Reply 1 : #4 plug popped out on the highway.
Some had luck with helicoil, other's don't.
What I would suggest if you have enought room is retap the spark plug hole to use a slightly larger threaded spark plug (with the same heat range and gap). Used grease to catch most of the metal shavings, tap the spark plug hole, clean the cylinder with compress air, screw in a larger spark plug. There is a risk with that, the problem is some will say it's impossible or shouldn't be done because the shaving would fall inside the cylinder and ruin the rings, piston, etc. That just one option.
Other options includes:
1) Installing Helicoil
2) Installing another/used cyliner head
3) Welding up the spark plug hole, dill out a hole, and retap the plug spark hole to the original thread with the cylinder head out (might as install a used head)
4) JB Weld/Glue the spark plug in?
Reply 2 : #4 plug popped out on the highway.
Use a timesert.
http://www.timesert.com/html/sparkplug.html
By far better than a helicoil and they sell kits for repairing spark plug holes. They work very well and are much stronger than a helicoil. By far the strongest economical option you have.
Reply 3 : #4 plug popped out on the highway.
Ok, thanks guys.
Have you guys or anyone else done a helicoil/timesert/other to the #4 plug on a 22RE WHILE the head is on? (wondering about clearances in that part of the engine bay...)
My brother works in a metal shop, so I could possibly practice it on something else a few times.
The spark plug screws back in, though it wiggles a tiny bit - would it be possible to try to use a mild threadlocker to keep it in place - or is that not advisable?
Reply 4 : #4 plug popped out on the highway.
The spark plug seals a shit ton of combustion pressure. If it wiggles, threadlock isn't going to do it.
Do it correctly with a threaded insert and be done with it the first time. You could get some long lasting iridium spark plugs and not have to worry about changing them again for 50k miles.
Reply 5 : #4 plug popped out on the highway.
What about a tiny bit of RTV?
Not trying to be a total redneck here, but time/money is in short supply for me right now...
It made it over a month from when I chased the threads to when it popped out.
What's the worst that can happen - for an insert, I'd have to tap it out anyways, right?
Reply 6 : #4 plug popped out on the highway.
Quote:
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Originally Posted by sevitzky 
What about a tiny bit of RTV?
Not trying to be a total redneck here, but time/money is in short supply for me right now... It made it over a month from when I chased the threads to when it popped out. What's the worst that can happen - for an insert, I'd have to tap it out anyways, right? |
dead easiest way is take it to a machine shop and pay them $150 or so to do it for you. done, no worries.
future:
prevent cross threading by using a section of hose on the end of the spark plug when starting it in the hole. then turn by hand. then torque with wrench. never, ever, ever start a plug or any bolt with a wrench. it will cross thread, and moof stuff.
use anti-seize, cause if you flunk out in college, you'll really need that truck to get you to your sloggin crap job like the rest of us... and you'll have to change the plugs eventually. ;-)
Reply 7 : #4 plug popped out on the highway.
when you cross threaded it and chased the holes, you removed material from around the hole and pushed the material of the threads around a few times weakening it. over the last month the repeated hammering of combustion pressure has not unscrewed but as you say, blown out the spark plug because the threads are not tight.
I think BEST case with RTV is it lasts a minute. Realistically I think it'll last till the engine fires. thread locker needs threads to lock, it won't MAKE threads and it'll be broken down by the heat of the engine the first time it runs for 5 minutes.
As mentioned your options are
-JB-weld it in (bad idea. probably won't last more than several weeks)
-thread insert (possible on the car though personally I wouldn't except as a last resort)
The time-serts look good. only problem is you can't get them in every auto parts and hardware store there is.
-new head ($$$, time)
-weld/drill/tap ($, time)
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