Seized spark plugs

Cammer8

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I've hot a 2010 Jeep Jk with 3.8 engine. The spark Plugs have around 100,000 miles on them. Running ok, but I'd like to change them and I'm afraid that with that mileage there might be a problem that they might be hard to remove. Any tricks that may be used ? I don't want to strip the aluminum head threads.
 

Dirty Dog

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Make sure your engine is totally cold. Pull your plug wires. Spray in a ton of WD40. Let it soak. Maybe do that again. Other than that, there's not much in the way of tricks for removing your old plugs.

Buy plugs from a reputable manufacturer. I mostly use Bosch and NGK. Do NOT put anti-seize on your new plugs until you check the manufacturers recommendations. Modern plugs have rolled threads, not cut, and are plated, eliminating the need for anti-seize.

From the NGK web site:
NGK spark plugs feature trivalent plating. This silver or chrome-colored finish on the threads is designed to provide corrosion resistance against moisture and chemicals. The coating also acts as a release agent during spark plug removal. NGK spark plugs are installed at the factory dry, without lubrication or anti-seize.

Anti-seize can act as a lubricant, altering torque values up to 20 percent, increasing the risk of spark plug thread breakage and/or metal shell stretch. Thread breakage can sometimes involve removing the cylinder head for repair. Metal shell stretch changes the heat rating of the spark plug and can result in serious engine damage caused by pre-ignition. Do not use anti-seize or lubricant on NGK spark plugs. It is completely unnecessary and can be detrimental.

Similarly, Bosch recommends against using anti-seize on their plugs. So does pretty much every major spark plug manufacturer.

I would, however, use plenty of dielectric grease on your new plug wires, especially if the Jeep sees any real off highway use. It improves the connection and prevents water entry.
 
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Cammer8

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I tried engine cold with several applications of Blaster and couldn't budge plugs. Contrary to most -I warmed up the engine and voila, it broke loose. I plan on easing out with more Blaser, using counter and clockwise to finish the job!!
 

Acxman

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Heat the block is what you want. No different then installing bearings. You heat up the surrounding area so that the steel/iron/aluminum Expands. I work on many small engines. When I remove a bearing or threaded part I always heat up the block around the part. Also when reinstalling a bearing, I heat up the block and put the bearing in the freezer for a few minutes. Sometimes the bearings fall right in without having to use the press.
 

macleanflood

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Reason manufacturers say no to antiseize is it throws off torque values and they don't want the liability. That and idiots can get it all over the electrode.

I use it...but I also typically use copper high heat.

Dialectic grease is good inside the boots.

Pull the plugs and post pictures. Always good to read the plugs...tells you how well the engine is running...or YouTube it. Vice Grip Garage often covers how to read plugs.

-Mac
 
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Cammer8

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The only thing that worries me is messing up the threads on the way out! Plugs have been in quite a while.Carbon deposits etc..could cause a problem on the (softer heads) when heated up!!
 

BLACKJKU

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The only thing that worries me is messing up the threads on the way out! Plugs have been in quite a while.Carbon deposits etc..could cause a problem on the (softer heads) when heated up!!

That's why i put just a light dab of Anti-seeze on mine, and i've never torqued a spark plug. I just run then in until they stop and then just snug them up a bit.
 
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Acxman

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Also, do not install plugs when the engine is hot. Works the opposite of removing. Tightening plugs ( or any threaded part ) when a block is hot will allow it to be tightened further then when it’s cold. That can be too tight.
 
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BigAL07

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Bungee the breather tube back out the way. Crawl up in there. Use the right size ratchet and u can get from the top without taking anything apart. Did it several times
 
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