I have a 92 Mits, removed #2 and #3 sparkplugs easily. But #1 plug is frozen and wont budge. Sprayed wd40 yesterday but still wont budge today. Tried removing when cold, also warmed the engine up...still cant turn it! I am using a 3/8 rachet as I haven't ever needed anything heavier on aluminum heads. Plug did seem to move a tiny bit once. Have tried it several times but still wont move. I am afraid if I use a 1/2 in drive it will Break Off! Just wondered if anyone out there has ran across this problem. Any advice would be appreciated as i'm just about stumped!! Thanks:frustration::
For penetrating oil you need something a little higher up the food chain than WD-40 IMO Try [In no particular order]: Deep Creep, PB Blaster or Kroil Oil. I did a quick Google search and it came up with a few methods. You could try using the pen oil of choice from above to soak the affected plug and let it sit then start the engine briefly - just enough to get the cylinder head to room temp - this should get the threads on the sparkplug and the head matched as close as possible Now you can try to see if the plug will budge. The hotter or colder the engine is the more the plug will be stuck from what I read due to the aluminum head having a different expansion rate so if you can get them both [plug + head] at room temp it is the best possible enviroment to try removal of the spark plug. Another theory I ran across more than once was using a impact wrench to get it out. The theory behind this was that the impacts break the bond between the steel shell of the plug and the aluminum of the block. The proponents of this theory suggest that turning out by hand gives chance to the threads in the aluminum head galling and getting even more stuck on the plug. What ever you decide - Good Luck
I dont think you would break the plug with a half inch. I've had to use one in the past with aluminium heads. aluminium tends to corrode when a differant metal is touching it. After removing it apply a antiseize compound to the sparkplug threads and dont over tighten. People always tend to over tighten plugs.
That brings up a whole 'nother debate that runs rampant on the net. Anti seize on a spark plug. The against crew: Not recognized by manufacture, The metal in the antiseize can short out the plug if to much put on and gets into the combustion chamber, Must reduce torque specs by up to 40% as the torque spec from factory is for dry fit. So the antiseize makes it even easier to strip the plug thread if not careful. The for crew: Sets up a protective barrier between the spark plug and the aluminum head making it easier to get the plug out next time This sums it up for when to use anti seize and when not to: Also see the NGK bulletin .PDF below
FWIW, i always use just a little bit of anti sieze on the plug threads going into an aluminum head. they have little packets of it at the checkout that is just for spark plugs, it may be dielectric to avoid shorting?
All New Plugs Are IN! Thanks to all you guys, better penetrating oil, a 1/2" ratchet, and the Mini Truck Lord!! Must be my lucky day as a friend stopped by who used to work for Mercruiser Marine in Stillwater, Ok and insisted on helping. Could I say no? (Mercruiser is where GM went to have the first Aluminum blocks and heads cast for the engines used in the Corvette.) Anyway, here is what we did. First sprayed it with "free" penetrant, drove the truck for about 2 miles to warm it up. Then sprayed carb cleaner on the plug to rapidly cool it down. Finaly, after getting it to turn 2 VERY slow rounds wih the 1/2" ratchet it started easing right out! The plug was very rusty & looked as if it had never been changed! Again thanks and I hope I can be of assistance in returning the favor later down the road. I did use anti seize and would highly recomend anyone changing plugs do the same!! THIS FORUM RULES!!
Joe, I like the comment about rapidly cooling the plug with carb cleaner. I was taught that trick by an old timer a long time ago and it really makes a difference. I've also used brake cleaner and an inverted can of keyboard duster/canned air, which will actually freeze things if you hold it upside down and spray out the liquid. dan
