Stuck spark plug - non vette

[71coupe]

Went to replace the spark plugs on my wife's car, Suzuki SUV. One of the plugs will not turn. I tried, but did not force it (aluminum head). It is a 4 cyl with a hemi style head & the spark plugs are directly in the middle of the valve cover. Do you guys have any suggestions? Thx

[mr.beachcomber]

There are no foolproof solutions that I know of; however, you might try this out first before taking it to a repair shop. Start the engine and warm up the engine to operating remperature. Shut off the engine, access the spark plug, and spray it liberally with PB Blaster. Allow the engine to cool down until it's cold, and then try to remove the spark plug w/o resorting to a breaker bar. If it's still unyielding, repeat the process. Start the engine, get it up to operating temperature, spray the spark plug with PB Blaster, and let the engine cool down again.

Personally, I would try this process up to five times before wrenching out the plug and ruining the aluminum threads. Worse case scenario is busting off the porcelain portion of the plug and leaving the base still treaded into the head. Either way, a replacement threaded insert will be required to repair the head. (Best done by a machine/repair shop.)

As a preventative, always use some type of anti-sieze on the spark plug threads as well as hand-threading the spark plug into the aluminum head until hand tight. Then use a torque wrench or 1/8 turn if you can't get the torque wrench to the plug.

Good luck!

[71coupe]

Cool - i'll try that. BTW, This thing has been running hot & that's why 2 plugs are tight. I did use some silver goop on them when they went in, but they've been in a couple of years now.

I was actually thinking about freezing the plugs to shrink them. I was thinking about using some dry ice & alcohol, but I may use PB blaster instead of the alcohol..