Stuck spark plug

[Jim in PA]

Once again I need feedback...
All feedback on other subjects has been very helpful and I hope y'alls can help me again.
I had recently asked the forum about vapor lock or ignition issues and had a great deal of helpful feedback so I decided to go ahead with tune-up along with installing the Pertronics electronic ignition module install.
While installing the spark plugs I found #3 plug frozen in place. (#1 and #2 plugs came out and went back in without any problem) With a standard length Craftsman ratchet wrench, 3/8" drive, I was unable to break the spark plug loose enough to remove it. I didn't want to Ape it out with a breaker bar for fear of wrenching the threads out of the head along with the plug.
#4 plug was tight coming out and took a bit of force the whole time to remove it. The threads looked good on the #4 plug and in the hole it came out of.
I lubed the threads in the head and on the new plug before installing the new plug in #4 and it still felt tight going in.
The engine is room temp. when trying to remove the plug. I know people that have pulled threads on a hot VW engine.
So far I have loosened the #3 plug about 1/10th to 1/8th of a turn at the most and squirted Liquid Wrench down the plug bore hoping it will soak in and the plug will magically be removed without being tight any longer. I will try again tonight or tomorrow.
The old plugs looked fine...(almost fuzzy brown) I have no issue leaving the #3 plug where it is until winter '09 when the planned engine rebuild will begin.
If I decide to Ape the plug out and end up pulling the threads out of the head along with it...can Helicoil be done with the head on the engine or does the head have to come off? I believe the head should be off to do Helicoil or any repairs.
What other technique can be used to remove the #3 plug without damaging the head or threads?
Thanks again in advance for your good help.
Jim

 

[sunalp]

Hi Jim, Spark plugs that are in the head for a long time can be challenging to get out. I haven't had that much of a problem with the Alpines yet, but did have similar problems with a BMW motorcycle, which is somewhat similar(aluminum head with steel plugs) I have helicoiled the BMW head with the head on the engine so I would assume it could be done on the Alpine without too much trouble. You just want to make sure that the aluminum shavings(when you run the helicoil tap) don't get into the combustion chamber. We used to load the tap with grease so the shavings stuck to the tap and went very slowly . That way we could catch the shavings before they went into the hole. I wouldn't want to rely on a Helicoil as a permanent fix. They do make inserts that are better and would probably last longer.
Hope that helps!
Cheers!
Steve

 

[Nickodell]

Why take the chance? If the plug rips out the head threads, take it off to be sure that you don't dump shavings into the combustion chamber when you Helicoli it. You can also then take it to a shop and have the Helicoil insert put in professionally. While it's off you can clean off any coke and check the valves and seats and if necessary lap them in. If it's a long-service engine, replace the valve springs too.

 

[puff4]

Hi, Jim -

Check your PM - I can stop over and have a look, if you like.

Cheers,
Kevin