# Stripped spark plug hole



## Av8or (Sep 23, 2007)

Changing my plugs yesterday on my 92 Jetta 1.8 8V and the threads came out with the plug.







Some nasty looking aluminum was in the threads of the plug i removed, it almost looked like sandy grease. The new plug won't thread into its hole. What is the best was to repair stripped threads on the 1.8? Why did it happen?







Only had about 15,000 miles on the plugs.


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## chickenfriend (Jan 31, 2005)

*Re: Stripped spark plug hole (Av8or)*

It happens. Could have been some electrochemical corrosion between the plug and the aluminum head, or the plug could have been overtightened, galling the threads.
Best way to prevent it is to carefully apply antiseize to the plug threads and reduce your torquing by I think it is 15-20%.
You can run a tap in the hole if you can get it started squarely. That might work good enough to repair it if the damage is not too bad.
Other option which is very common is to helicoil the hole.


_Modified by chickenfriend at 8:45 AM 12-4-2007_


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## RoccHead (Dec 22, 2003)

*Re: Stripped spark plug hole (chickenfriend)*

You can buy specific spark plug thread repair kits that come with a tap, and inserts. It's a good idea to clean the smoo from around the plugs before you take them out, clean the holes and never-seize the plugs. I seem to have found that if you torque the plugs to the spec of 22 ft-lbs, they will eventually strip. 15-18 seems to be a better number. Pretty much what Chickenfried said already


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## Av8or (Sep 23, 2007)

*Re: Stripped spark plug hole (RoccHead)*

Thanks for the help, I'll try the tap first but probally end up using the heli coil. The hole looks pretty bad. 
Over the last year or so the wealth of knowledge that I've gained from this forum has helped me and my prescious VW out tremendously. Thanks


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## Jettaboy1884 (Jan 20, 2004)

*Re: Stripped spark plug hole (Av8or)*


_Quote, originally posted by *Av8or* »_Over the last year or so the wealth of knowledge that I've gained from this forum has helped me and my prescious VW out tremendously. Thanks









I'll second that. http://****************.com/smile/emthup.gif Whenever TCL, or the Mk2 forum disappoints, I come in here for some good informative reading. (Mk1 forum is pretty tight, and from what I understand the Scirocco forum is even tighter)


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## Av8or (Sep 23, 2007)

*Re: Stripped spark plug hole (Jettaboy1884)*

I found a Heli Coil kit pretty cheap 20$ I need the 14MM kit correct?




_Modified by Av8or at 5:07 PM 12-4-2007_


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## eurowner (Jan 26, 2002)

Please, buy the specific spark plug stripped hole kit, not a Helicoil kit.


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## Av8or (Sep 23, 2007)

*Re: (eurowner)*

This kit says it is a spark plug port repair kit. What do you reccomend? Been doing some searching and the prices vary from 20$ up to around 450$ I think it will get the job done, or will it? Is 14MM the right size?


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## Jetta A2 1989 (Sep 7, 2004)

*Re: Stripped spark plug hole (Av8or)*

Check around some local auto machine shops, many will do the repair on the car, and the price may be reasonable.


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## RoccHead (Dec 22, 2003)

*Re: Stripped spark plug hole (Jetta A2 1989)*

The plug repair kit that I have is made by Helicoil, as shown above. 
You can take it to a shop and many of them can do it. Most likely they won't do any different than you will. If you can sneak a vacuum nozzle next to the hole when tapping you might reduce the chance of getting chips into the hole. If you set the crank position so that cylinder has the valves closed, you can blow it out after an maybe get the chips out. Most shops aren't going to bother with this.


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## Av8or (Sep 23, 2007)

Got the one from Autozone, 30 bucks. Turned out better than i thought it would.


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