Broke spark plug....grrr....2165cc Volkswagen

[STINEY]

Had a cylinder on the green Sandrail go dead this past summer. Plug was stuck, so we drug it home and I have been soaking it down for the last 5 months with PB Blaster and a mix of ATF and Acetone.

Have been trying to tighten and loosen it off and on for those 5 months to no effect at all.


Last week I decided enough soaking, and that if the threads were going to pull out so be it. Got the breaker bar out and got on it seriously, fully expecting the threads to strip out. (its somewhat common on these VW aircooled heads anyways)

Instead the $#*@ plug threads snapped off. SERIOUSLY? Welcome home Murphy, we've been missing you lately.





My buddy Jim loaned me this set of shouldered extractors to try. The plan is to install the extractor, get a good bite, then remove extractor and try to get a torch tip down there to heat the plug thread piece. Then reinstall the extractor and cross fingers (maybe sprinkle some holy water on it first?)



I've never had one stuck this bad before. The other three are perfect, Go figure.

[squirrel]

don't take long to remove a head on that, does it? I would do that first, get it out on the work bench where you can work on it...

[Deaf Bob]

Protuding threads in the cylinder does that every time..
Do you use anti-seize?
Mostly al- ferrous does it too.. Hot spark welded the plug in?

[STINEY]

Yes to anti-seize. This hole MAY have a thread insert in it. I seem to remember that these aftermarket heads had them installed by CB performance as a preventive measure.

This is the 2165cc bored stroker twin-weber mill. I built it around '95ish.....low miles but lots of high RPMs. Other than a cocked valve seat once it has been trouble-free.


Welded plug in? Maybe. I've never seen one stuck this badly before, and the ones I have seen stuck were always zero-maintenance junker types. This thing has been babied, always indoors, regular check-ups, etc.

[TheSilverBuick]

I echo Squirrel. It sounds like something got into the chamber and beat the end of the plug or something physically sticking it to the chamber.

[STINEY]

Maybe some sand got on the threads? Maybe the sand "glassified"?

Not that there would be any sand around it.....never that....

At what temps does sand melt?


Edit: Sand melts at 3090 F...........probably not the issue here.

[JamesMayberryIII]

Yes to anti seize . but what type you use .not all types are for all metals...
That break looks like a plug that was dropped at some point.. or that backed off and vibrated in the whole..
Not knowing where the plugs are in your buggy and if there is any protection.. It could've got whacked while playing ..

[Deaf Bob]

Edit: Sand melts at 3090 F...........probably not the issue here.

Combustion chambers go as hot as 14,000* in turbo diesels... "kaboom range?". I always backed off at about 10-11,000*.

[STINEY]

Yeah, but.....the aluminum that the head is cast from melts at 1220.....so I figure some sand inbetween the head and plug is fairly safe from melting.

Speaking of heat and melting - what the heck are spark plug threads made of? I just came in from a heat-n-beat session on the offending part and while I did no further harm, I also was unsuccessful in getting the plug body to glow orange.

It seemed to glow a neat iridescent bluish tinge, but anything resembling orange or red was definitely not happening.



Was heating with oxygen /acetylene with pencil tip directed at the inner circumference of the plug thread body.

[Dan Barlow]

I had a friend break one off like that in a ford ranger about 2 months ago . Ended up getting it out with an extractor . And maybe an impact .

[STINEY]

I'm thinking of trying again with a can of FREEZE substituted for the torch heat.


Those shouldered extractors are awesome. They bite extremely well, and I was nearly lifting the rear of the buggy with a 3' extension on the breaker bar. The extractor never slipped. Impressive.

Equally impressive is how badly the threaded section is stuck.

[squirrel]

pull head, take to machine shop, they can set it up in the head machine and drill it exactly on center, at the correct angle

[malc]

After reading this I popped out to check my spark plugs.......just fine......all finger tight..😂😂

Getting Helicoiled are we ?

[Deaf Bob]

I have to agree with Squirrel, you might rip a chunk of a hole in your head, then what? Whole new head?

[JamesMayberryIII]

hit the head with nos to freeze it, then a little heat on the plug ,and it will come right out..