Plug came out with metal in the last 3 threads, what now?

[sniper]

I was just pulling the plugs out of my motor and the #8 was being trouble some, i really had no choice so i just kept backing it out, when it came out, the last 3 threads of it were solid stuck with metal in them. My guess is that i destroyed the theads that the plug uses. Now what do i do? im going to pull the heads off soon so i can get a better look at whats going on but my guess is that the plug hole threads are shot. Can i just re tap and pray it holds? is there any way to repair this or do i need another head? i really really hope i dont need another head...........

 

[MaxPower]

You can get it heli-coiled. Engine reconditioners or transmission shops can do it for ya. It replaces the original thread thats tapped into the head with a steel coil that becomes the new thread, its stronger than the factory tapping into the alloy.

 

[Zuffen]

For a stronger insert look at Timeserts (?).

Thery actually remove metal and insert a plug with the sparkplug threat in it.

They use timeserts to save Porsche 911 blocks when the head studs pull. Common problem in the late 70's. Helicoil can't do the job as the pressure is too great.

 

[TundraEddie]

Since you're pulling the head anyway,I'd try retapping first. If that doesn't work timesert it,they are definitely stronger than helicoils. Or if you know of a good welder (or head porter or machine shop),TIG weld and retap.

Here's a link for timesert's sparkplug kits http://www.timesert.com/html/sparkplug.html

A former coworker used them on a Caddy Northstar motor when half of the head bolt holes stripped...Caddilac themselves recommend using timeserts for such a job.

 

[Lextreme II]

I have a driver head at home if you need it. FREE However, my passenger side is cracked.

 

[sniper]

ya im going to try and re-tap it and see where that gets me. Then ill just take Lex's old head :- D

Anyone know the size of the plug?