2004 Saturn Ion spark plug seized!

Went to change the plugs in my Saturn Ion (2.2 Ecotec) last night. Started at the right (passenger) side of the engine and got the first three with little problem. At the last one (driver's side), though, I ran into trouble. The plug didn't want to turn at all. I finally got it to break loose, but it wouldn't turn very far before hanging up again. Not wanting to strip the plug hole, I threaded the plug back in as tight as I dared.

This is the first plug change I have done on this car, as I have only recently taken possession of it. I always use anti-seize on spark plugs, especially in aluminum heads, but whoever put these plugs in did it dry.

I know there are spark plug thread repair kits available, and I don't have a problem using one, although I'd rather not. Does anyone have any advice for removing the seized plug WITHOUT removing the head or stripping the threads? And/or if the threads do become damaged, has anyone installed a thread repair kit with the head on the engine and done it sucessfully (no further damage)? I really don't want to remove and/or replace the head! Thanks in advance - Chris

 

Try putting the remaining plugs in and starting it, run it up to operating temperature, shut it off and wait about a minute (this elevates the head temp up as high as you'll get it). Then try to remove the problem plug while the engine is hot.

 

Okay, I'll try that. Last night, I started changing them after driving the car home about 11 miles, then a brief delay to eat dinner. The engine was on the hottish side of warm at that time. I have heard that temperature is key to plug removal with aluminum heads, but I couldn't remember which way was best, cold or hot. I'll try again with it hot.

 

It is best to remove spark plugs from a cold aluminum head. Since you can't get it out on a cold head you might as well try a hot one. You may have to install a thread insert for the spark plug. If you get the plug out and the threads come with it have you considered how you are going to get it somewhere for a repair?

 

Okay, that's one vote for hot and one for cold... I can do the work myself, at home in my garage, I just would rather not! Actually, last night I was thinking cold was how I wanted to pull the plug, and a mechanic where I work said cold was the way to go,too. Think I'll try it in the morning, after the engine has cold-soaked overnight...

 

if you need to install thread inserts, turn that cylinder to top dead center with the valves closed, insert a rag into the spark plug hole to help keep aluminum chips out of the chamber and use grease on the tap, be very careful to retain the tab if you use a helicoil kit and not let it fall into the chamber, then blow out the cylinder after pulling the rag out. i have done this successfully to a couple of heads, use locktite on the helicoil insert when installing it and antiseaze on the plug and you shouldn't have any problem with the new threads unscrewing when it comes time to replace the plugs again.

Murphy was an optimist

 

Thanks, Speedwrench. My mechanic co-worker suggested grease on the helicoil tap as well. Rather than blow any chips out the plug hole, I have an air-powered vacuum I thought I would rig up to fit through the hole (flexible nylon hose to chase around the top of the piston) to try and keep from embedding anything in the piston or lodging anything in the top ring.