started my engine with new champion x plugs and then i saw at number 2 some bubbles (see arrow). Is this normal?
The technology is 100+ years old. Originally there was a copper / asbestos seal. The design is now made without asbestos. It doesn't work as well, but it works OK. You should not worry too much about the bubbles.
Is it possible to unscrew them and put a seal in there?
I'm thinking there is probably a seal in there. I might try gently tightening the gland nut.
I recently had one come loose and out as I was driving. I put it back and tightened it down with a wrench. Worked fine til last week. Someone was looking at it at a display and called my attention to it being loose again. Think I'll put a drop of Loctite on it.
How can i disassemble this spark plug? Have you some pictures?
Michael, I fasten the smaller nut part in a vice, the spark plug upside down (don't tighten too hard, the porceline part is brittle) - then I loosen the base with a wrench. Since yours are new I don't think there is reason to disassemble them, I'd try just tighten them first. If they loosen up again I would check them up or use locktite as Mike suggests.
A small bubbling leak doesn't affect the car's performance much - but I understand it's much nicer to get it tight & tidy
On the left is a modern X. Note the tiny copper ring. On the right is an old low head X from around 1920. Note the copper gasket with asbestos inside. This is no longer available. In the center are a couple of the copper crush gaskets I'm gong to try when I get one of the T's running again.
I got them from:
Genuine Aircraft Hardware Co.
4250 Aerotech Center Way, Unit B
Paso Robles, CA. 93446
Phone - 805-239-3169
Fax - 805-239-4871
Email - email@example.com
They're part #MS35769-9, size 3/4" OD & 1/2" ID.
Everything, including porcelain, expands with heat. Beware of over-tightening.
I just installed 4 nice brand new Motorcraft plugs, 2 out of the 4 leaked around the crimp on top. And to think I put the new ones in because I was tired of the leaking Champions!
I see the new ones only have one simple copper washer under the porcelain, leaving the upper steel bearing directly on the porcelain. I would feel better if they had a second copper on the top side of the porcelain. More to crush as the upper and lower steel parts are tightened with less chance of center breakage.
Also, you should try some of the originals you have.
Michael, I just take them apart with two box end wrenches. One 15/16, the other 13/16.