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I am about to replace the plugs on my 06 4.7. Do I need to put antisieze on the threads?
 

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it doesnt hurt. especially if you plan on changing them again. i also use dielectric grease on the end where it attaches to the coil packs
 

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One of the times I swapped out the plugs on the Commander I forgot to buy antisieze and installed them without it. It didnt cause any issues but since I have been using it.
 

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I know this is a really old thread but had a similar question.... and hate to see dozens of threads, all asking the same thing. I have a 2007 Hemi and will be swapping plugs tomorrow, for the first time. It has the steel head and the Champion 570 plugs that don't use a crush washer. I understand that the use of anti seize requires about a 25% reduction in torque and not to get carried away applying it.

I know its important especially on aluminum heads but just wanted to confirm that "everyone" uses a little dab of anti-seize on their spark plugs threads, no matter whether they are aluminum or steel heads.
 

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Anti-seize s not required nor is it a good idea for use on sparkplugs. I know it is commonly used but I have personally talked to Engineers at sparkplug companies both at Champion and NGK whom have stated not to use it. Modern sparkplugs are plated so that the threads do not require lubrication in either aluminum or iron cylinder heads. Anti-seize can also act as an insulation layer that can insulate the plug from the cylinder head and keep the heat from the plug insulator from being transferred to the cylinder head thereby effectively increasing the heat range of the plug. If you feel that the plug threads must be lubricated graphite should be used. Champion years ago used to sell a sparkplug thread lubricant that was essentially alcohol with graphite mixed in it. The graphite will not interfere with the heat transfer of the sparkplug. You have to be careful though not to get any graphite on the sparkplug tip or insulator as graphite is electrically conductive and cause plug misfiring. A lubricated sparkplug thread will reduce the needed torque value by 20%. It is easier to strip sparkplug threads that have been lubricated from over-torque.

Dan
 

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I have a 2007 Hemi and will be swapping plugs tomorrow, for the first time. It has the steel head and the Champion 570 plugs that don't use a crush washer.
Pretty sure all Hemi's in Commanders have Aluminum heads on the engines. My 06 does.
 

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I would be shocked if any Gen III hemi had iron heads, I'm near positive all heads are aluminum.

If you're judging by the spec for tapered or gasketed spark plugs, yes its more common to use gasket on aluminum and taper on iron heads, but that does NOT mean its an iron head just because its a taper plug, they can be used on aluminum. The length of the threads is indicative if it is aluminum or iron, short thread section would be iron that can be torqued tighter in the stronger/harder iron, and long thread section would be aluminum that needs to spread the torque over a greater area for the weaker/softer aluminum. I would also double check the listing and check other sources if you're reading your Hemi calls for tapered plugs, it may or it could be a mistake in the listing or part number in the one source you're looking at. As well, I would go with what you find OEM in the Hemi, i.e. it came from the factory with gasket spark plugs, that is what I replace it with.

Anti-Seize has fine metals in it, heavy metals, that act as sacrificial anodes to prevent the corrosion that seize the threads, so it conducts heat and electricity well. True, probably NOT as well as steel to aluminum, but well none the less, I have yet to see anyone report a problem from anti-seize.

The steel and aluminum are very prone to corrode when they touch, dissimilar metal corrosion, through in the high heat and pressure that promote corrosion and through the electricity flowing through them (corrosion is an electrical process) corrosion is very possible.

I have witnessed galling of the threads when removing spark plugs, perhaps they were NOT plated plugs.

Plating can corrode away as well. To be honest I just don't have enough experience and knowledge about spark plug to say if the manufacturer claim the plating will prevent corrosion in all cases holds up or NOT.

One thing to consider, I do use anti-seize on brakes (between the hub and rotor) even though the manufacturer recommends NOT to. Since the run-out tolerances are so tight, they worry dirt trapped in the anti-seize could put the brakes out of tolerance for run-out. Of course they don't have to deal with rotors seized to the hub. What I've done is to use just the tiniest amount of anti-seize, just rub a stain of it on with a cloth, and that is all it takes to prevent the seizing.

People often use way to much anti-seize, totally coat all the threads, have it squish out all over. Honestly, and especially if you have a plated plugs, you need less than a tiny dab, just a barely any on the beginning of the threads, that will spread as you run the plug down into the head.

Using a torque wrench with lubricant on the threads is a great way to strip out the threads. All torque specs are assumed to be dry torques unless they specify they are a Wet Torque. Head Bolt Torques will specify they are wet torques. So, you have to reduce the torque spec if you use anti-seize.

Don't worry about undertorquing spark plugs, there is a lot of thead on plugs and that holds even if you use less than required torqued. It is far more common for people stripping out spark plug threads in heads than it is for plugs backing out, or the almost unheard of, plugs being blown out of the head from pressure/compression.

Personally, I follow the instructions on the box for the spark plug, finger tight then use the wrench/breaker bar to turn a certain amount of turn, usually a half turn (180°) for gasket plugs and a 1/16th a turn (20°) for taper plugs. And experienced guys can do plugs without a torque wrench, you can feel the torque steadily increasing as the wrench turns, then you'll hit a point where the wrench stops turning and the torque needed to turn it goes up at a much greater rate, that is where you stop, you want to put some more torque on the threads but NOT turn the wrench much, i.e. the plug is bottomed out and you're just putting pressure on the threads, at that point you just need a few degrees of turn, more, you're going to strip out the threads, just enough to be a firm pull on the wrench handle and NOT move more a few degrees.
 

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Oh, Anti-Seize also contaminants and ruins O2 sensors and Catalytic Converters. Slather Anti-Seize all over the plugs and it will get into the cylinder and it will go out through the exhaust and into the O2 sensor and CAT, shortening their life. All the more reason to use the Anti-Seize sparingly, we are talking you can barely see a light layer on one tiny spot on the threads is all you need.

The latest motor oil spec has removed zinc additives, since almost all engines on the road have roller tappets now and thus can live fine without the high pressure zinc additives. The reason why they pulled it out of the oil, the little amount of the motor oil that will go out the exhaust was shortening the life the O2 sensors and CAT.

If you own a classic car or very old car that has the older flat face lifters, the oil on the shelves today do NOT have the additives that they need. This has been a big discussion with the Classic Car guys. If the motor is broken in, they can get by, but guys that have just rebuilt their 60's V8 have had the whole cam and lifters totally ground down, because the modern oil they used didn't have the additives that protected that kind engine operation.
 

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Anti-Seize has fine metals in it, heavy metals, that act as sacrificial anodes to prevent the corrosion that seize the threads, so it conducts heat and electricity well. True, probably NOT as well as steel to aluminum, but well none the less, I have yet to see anyone report a problem from anti-seize

I have witnessed galling of the threads when removing spark plugs, perhaps they were NOT plated plugs.

People often use way to much anti-seize, totally coat all the threads, have it squish out all over. Honestly, and especially if you have a plated plugs, you need less than a tiny dab, just a barely any on the beginning of the threads, that will spread as you run the plug down into the head.


Personally, I follow the instructions on the box for the spark plug, finger tight then use the wrench/breaker bar to turn a certain amount of turn, usually a half turn (180°) for gasket plugs and a 1/16th a turn (20°) for taper plugs. And experienced guys can do plugs without a torque wrench, you can feel the torque steadily increasing as the wrench turns, then you'll hit a point where the wrench stops turning and the torque needed to turn it goes up at a much greater rate, that is where you stop, you want to put some more torque on the threads but NOT turn the wrench much, i.e. the plug is bottomed out and you're just putting pressure on the threads, at that point you just need a few degrees of turn, more, you're going to strip out the threads, just enough to be a firm pull on the wrench handle and NOT move more a few degrees.

Years ago when Champion was involved more directly in racing they used to send sparkplug engineers to racing events to aid the tuners. At the time I was racing in the Superbike class at Laguna Seca and was tuning one of my bikes and I was working with a Champion engineer. When doing plug readings to determine proper fuel mixture jetting for track conditions the topic of anti-seize came up as he told me that using anto-seize would effect plug readings and tended to increase heat range if used. I would not consider this a big issue but woth considering.


Most plug galling is caused by the plug being overtightened at some point and having the threads weakened to the point of shearing and the loosened thread jamming and locking the remaining threads as the plug is removed. Proper torque will prevent this and Mongo's recommendation of using the plug manufacturers directions is a good one.

All modern sparkplugs are plated to prevent corrosion and seizing in dissimilar metals. some are a more bright type plating as most of the Japanese plugs and some are plated as the AC or Motorcraft plugs and are dark or black in color.
 

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Thanks for all the replies. I'm going to swap plugs in just a couple of minutes for the first time on my Hemi and figured now was the time to ask questions.

I think I'll just give each of them a little dap of antiseize as suggested by some, just enough at the start of the threads, to allow it to spread around. I'm used to feeling how tight to get the plugs on my older cars, so will likely rely on that feeling more then an actual torque value.

I just picked up a Craftsman beam torque wrench yesterday, that measures in 2.5ft/lbs increments so I'll probably just check to see I have them around 11-12ft lbs. with the the anti-seize applied vs the 14 or 15 max dry.
 
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