I changed my plugs tonight - 7 of the 8 anyway. #5 appears stuck. How hard can I crank on it before damaging the threads in the head or breaking the plug off? I soaked it in PB blaster before giving up on it for the night and will try again in the AM. Any other tricks? I'm using the factory wrench, if that matters. Thanks.

 

Not much. Spark plugs typically develop deposits in the threads that can make removal tricky. An experience mechanic can usually tell when the threads of a bolt or spark plug are beginning to bind, and will stop before applying too much force to damage the threads or shear the bolt off completely.

What you need to do now is incrementally tighten and loosen the spark plug until the binding works free. Hopefully, you haven't already damaged the threads in the cylinder head.

 

were you taking the plugs out when the engine was hot or warm?
that could be enough to cause the plug to bind up .
If you were removing them cold then you have other problems.
BUT when you say stuck does that mean it didnt turn at all,
or has the plug moved and then bound up, you can try to tighten it, then loosen.

if you get it loose make sure that you have already blown out the well with compressed air then added some PB blaster put a rag over the hole when you blow it out so any debris dont go flying all over the car

 

Won't budge at all. Tried again this am after soaking overnight in pb blaster, engine is stone cold. Yes, spark plug well is cleaned out with compressed air.

 

how big A boy are you?

What you using for a tool?







Roy D Mercer

 

Factory tool:

 

If that means the one from the tool kit, re-try with a real spark plug socket and ratchet with some leverage.

 

The factory tool is kind of a emergency use only tool.
Please do not take this the wrong way, but if that is all you have in the tool department, I would suggest that you take the car to a mechanic.

They do not have to be a 928 mechanic, but they will have tools, tricks and knowledge that you do not have. (some will any way)

A very good product for getting carbon off of the threads in either GM top engine cleaner or SeaFoam, but you have to have some movement of the plug for it to really work, just put a small amount down in the plug well, enough to have maybe a 1/8-1/4 inch at the bottom.

Good luck.

 

I have never done this before and have never had this problem, but if I did I think I would buy a six point socket to fit the sparkplug, a long one, or even a sparkplug socket as suggested above. I would get one with a half inch drive. Then I would also get a short extension just long enough to extend above the valve cover. Then I would also buy one of those impact driver items that has a half inch drive on one end and that you hit with a hammer on the other end. Put it all together and slip it over the spark plug then crank it with your hand in the counter clockwise direction and hit it sharply with a hammer. If you have to buy the hammer, get one that is fairly hefty.

I think this method is better that the hefty leverage method because of the shock effect of the hammer blow which I think will be real advantageous in breaking the corrosion that has the plug locked in its threads. I think putting a lot of leverage on it may be just too slow to break the bond.

Hope it works.

Jerry Feather

 

No worries, I have plenty of tools. I was just using the factory tool since it fit nicely and had no problem with the other plugs.

My question was more about how much torque can I apply before causing damage.

 

Plug is out, bigger tool required. Was just nervous since this plug required much more to break free, and didn't want to damage the threads in the aluminum head. Thanks for the encouragement. I know changing plugs are about simple a job as they come - I also know the consequnces of ruining the threads in the head.

 

A visit to the Brew Pub and a longer lever calmed your fears and brought success!

 

That depends om how good the treads are, but it can range from not very much to a whole lot, it is more of a feel thing.

 

Thanks. Once I got the leverage, I had to go easy, a bit at a time, back and forth, until I got to the point whare I could spin it out by hand. Steel in aluminum threads always makes me nervous - especially since the other 7 came out without a hitch.

 

and of course you will put some of that thread goop on the ones that are going in to prevent galling