HeliCoil Problem

[cobralee]

I have aluminum heads and one helicoil. When I pulled the plugs, the helicoil came out with it. I understand I need to coat it with loctite and screw it back in.

Anyone know what loctite to use.

Thanks.

[dalola]

Cobralee,
If done properly, a Helicoil should not come out. Before using Loctite, you may want re-tap the thread, and try a new Helicoil of the known proper size. Remember, Helicoils use a specific , matching drill and tap. I suspect whoever did this initial repair used the wrong drill and/or tap, in which case, you may very well need to resort to unconventional methods. Also, a little anti-seize compound on the plug threads is cheap insurance!

Dave

P.S. In general, I would recommend Loctite 262 or 272, but you may want to confirm your application with Loctite, 800-562-8483.

[Roscoe]

Also you should use anti seize compound on the plugs. This may prevent it from sticking to the helicoil.

Roscoe

[Rick 427 Cobra]

Not all spark plug inserts are Heli-coils. Heli-coil is a brand name of a particlular style, a stainless coil with a patented locking arrangement. Other styles are usually little more than a threaded sleeve which, if not done properly, can easily remain on the plug when removed. I can not imagine a true heli-coil coming out without total destruction.
Regardless of the insert or head material, as Roscoe says, use anti-sieze
If there are still good threads in the head you can usually just reinsert the thread-sert kind.
Rick

[cobralee]

Actually, it wasn't a helicoil, but a threaded sleeve. So, as many of you recommended, I used loctite 271, which is specific for "thread locking". I'll find out tomorrow if it sticks or not.

Thanks for the input.

[JAM1775]

I would use blue loctite on the outside of the helicoil or insert where it contacts the head. Then use anti-seize on the spark plug thread. This should facilitate removal of the plug with the insert remaining intact.

[cobralee]

Jam-

Thanks for your suggestion. I already used the 271 loctite, so if that doesn't work, I'll go with your idea.

Thanks,

Ron