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Discussion Starter #1 (Edited)
Greetings,

I can't seem to find a good guide out there for people to follow for spark plug replacement, so I would like to fill that void. I can't imagine the 6.1 and 6.4 would be too terribly different from this guide, but maybe someone could chime in on that if there are any major differences.

Difficulty level of the job isn't too bad. I'd say maybe 4/10 for a person familiar with mechanical experience. Maybe 7/10 for a person that has little/no mechanical experience. Expect the job to take about 2 hours from start to finish.

Reasons why you would want to DIY:
1) Money. By DIY you will spend about $75. To have a shop do this, you're probably looking at $300.
2) I don't like other people touching my car for a job that I'm capable of doing myself. Others are not going to treat her the same as I would. Perhaps you would feel the same.
3) You get that special bonding time with your road buddy.

Tools you will need:
1) 5/8 Spark plug socket. It has rubber inside it.
2) 2x 3" ratchet extensions. At least one needs to be a locking extension.
3) Ratchet wrench
4) Torque wrench
5) 10mm socket
6) Gapping tool. I used a feeler gauge.
7) Needle nose pliers. I used a 45* long handled. Use a pair that gets a nice strong bite.
8) Q-tips and an acid brush
9) Anti-seize
10) Di-electric grease

You'll need 16 spark plugs. I went with the mopar plugs. P/N is 4-SPLZFR5C11

Most tools are shown below:




First thing you need to do is gain access. Remove your engine cover. Pull up on the front and then on the rear. It's just held on by 4 ball mounts.



You'll see the coil packs now. There's 8 of them. Each are held on by two 10mm bolts. Break them loose and you should be able to unthread them the rest of the way by finger. Remove them both, take care of the washer under the bolt head.


Wiggle the coil pack back and forth a bit while pulling away from the cylinder. You'll hear a suction sound as it separates from the spark plugs.


Your spark plugs reside in these two deep holes.


Afix your locking 3" extension to your 5/8 spark plug socket and feed it into one of the holes.


Put your other 3" extension on at this point and push straight down into the hole while twisting until it seats down onto the spark plug. Put your ratchet on now and remove the spark plug. They are probably in there pretty good. High removal torque in tight spaces plus knuckles... try not to loose too much knuckle blood and skin.


After you break the spark plug loose you can remove your ratchet and just thread it the rest of the way out by hand. When it's loose from the cylinder head, remove the top 3" extension and remove the locking 3" extension, the spark plug socket, and the spark plug.


Prep your new spark plug to replace the one just removed. Gap it first to .043". For feeler gauges you can stack two feelers to make your .043" like so.


A .043" gauge should fit nice and snug in the spark plug. If it's too tight or too loose, very gently bend the L tang to achieve .043"


Put your spark plug into your spark plug socket and 3" extension. (Note the knuckle buster I was warning about:werd:)


Using your acid brush, apply a nice thin even coat of anti-seize to the threads of the spark plug.


Now very gently and carefully slide the new spark plug on your 5/8" socket and 3" locking extension down into the cavity. Thread the new spark plug into the cylinder. Make sure you are careful here and you are straight. You definitely don't want to cross thread. You should be able to easily turn the spark plug several full rotations.


Now put your torque wrench on to finish the spark plug install. Torque is 12-14 ft/lbs (144-168 in/lbs). I went with the middle of the road at 13 ft/lbs.


If you have a second locking 3" extension then that'll make extraction much easier. I didn't have another handy so I used a nice set of needle nose pliers to carefully grab the extension and rock it back and forth while pulling until the spark plug socket releases from the spark plug.


Repeat the same for the other exposed spark plug. After that, you'll want to put a thin coat of di-electric grease on the inside of your rubber boots. Take care that you only apply a very thin coat inside and that you don't get any on the metal contacts. Di-electric grease is an insulator, getting it on your conductors would be self defeating.


Now just slide your coil pack back into place and secure it back down with the two 10mm screws/washers. Torque on the 10mm screws is just snug. Don't crank it down too hard.

That's it! 7 more to go.

Drivers side spark plugs were much easier to change. Passenger side most forward and furthest aft were the most difficult cylinders, but not too bad. Fuse box is slightly in the way on the forward cylinder and this thing pictured below was in the way on the aft. Honestly, I can't think of what that thing is lol. Anyways, you can slide it up and over the mounting bracket and push it out of the way a bit.


Now things wouldn't be normal if there wasn't at least one wrench thrown in the spokes at some point, right? Thought I'd share what happened as I was starting on my 5th cylinder spark plug install. Installed and torqued the spark plug, went to remove the spark plug socket and 3" locking extension and how convenient... my 3" locking device became weak and no longer has the locking strength to pull out the socket. What to do? Just put an extension back in there and remove the spark plug. Tried to install and remove my socket a few times, it wasn't going to work. What to do now... panic? Nah, grab the super glue! :browsmiley:


Temporarily fused my 3" extension and spark plug socket into one piece. Good enough to finish the job off. :guiness:


This change took place at 35.5K miles. There were a good number of 'spirited' miles in there too. Manufacture recommendation is at 30K miles. I wouldn't go much beyond 36K. After changing the plugs I noticed a definite difference in the throttle response. It seemed like there was some restored power.

Here's a picture of an aft cylinder removed spark plug. It looked pretty worn and was definitely due to be changed.


I hope this helps!
Dave
 

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Nice write up. I would have loved to had your pictures when I did mine.

I found that it helped to have a swivel or two to get the aft plugs on the passenger side. And, I fell in love with the magnetic spark plug socket that the guy at AZ recommended compared to my old one with the rubber insert.

Finally ..... NGK issued a bulletin advising against the use of anti-sieze. It felt weird not to use it, but when in Rome.....errr....Tokyo. I'm 55 and used NGKs in my motorcycle back in the '70's, but would never have put them in my '68 Charger. However, I had a couple of mechanics that I really trust tell me that NGK was the way to go for a stock 5.7.

I also noticed a marked improvement in performance after the plug change. And that was at 28,000 miles. I bought this car a year ago and it only had 11,300 miles on it and it feels far more responsive now than when I picked it up.
 

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Nice write-up! Thanks for posting pics of the process. :)

As was mentioned, NGK (OEM for our plugs) says not to use anti-seize on the plugs. The issue is the anti-seize allows overtorquing when you don't realize it and the plugs can snap off inside the head.

http://www.ngksparkplugs.com/pdf/tb-0630111antisieze.pdf

Something else I'll mention is that our plugs use crush washers and for new plugs I'll do what the box says (contact then 1/2-2/3 turn) instead of torquing them down in order to ensure the crush washer is properly sealed and also ensures the plugs aren't overtorqued if using anti-seize. If reinstalling a used plug then obviously you don't want to use that method. :D
 

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Another trick you can use is to use duct tape to secure the socket to the extension(s) so the socket doesn't get "stuck" in the head. ;)
 

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Discussion Starter #5
Very interesting find guys about the service bulletin on anti-seize. I can't say I would feel right not using it still though! Kind of like going against everything you've ever known lol.

I should mention though I did keep track of the torque in ft/lbs as well as turns after hand tightening. The spark plug box recommends 1/2-2/3 of a turn to tighten. 13 ft/lbs was right at about 2/3 of a turn. So in my personal observations, I didn't notice any allowance of over-tightening by using the anti-seize.

I'm not sure how that special anti-corrosion coating really works or if it would continue to hold up even if you are a little delinquent in changing plugs. Even after reading the service bulletin, I'm still on the fence. As long as you were to stay as close to 2/3 turn tighten, I can't imagine any negative impacts, only positive next time you remove. Definitely thank you for bringing that up though!
 

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I did this a few months back and wish I would have had this guide handy. All in all not a very difficult process, just a bit time consuming since we have soo many spark plugs! :) Not to mention those back 4 are a PITA!
 

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Torque specifications:
Spark Plugs - 13 ft.-lbs (156 inch-lbs)
Coil Pack bolts - 8.75 ft.-lbs (105 inch-lbs)
1 ft.-lb. = 12 inch-lbs.


The use of anti-seize compounds on spark plug threads that have a metal shell plating (i.e. Zinc or Nickel plating).

Applying anti-seize to the threads of spark plugs that have a metal plating allows the installer to mistakenly over-tighten the spark plug in the cylinder head; This stretches and fatigues the threads of the spark plugs, causing a much higher probability that the plug will break during installation or in some cases upon removal.

For spark plugs with special metal plating simply do not use anti-seize on initial Installation.All NGK Spark Plugs are manufactured with a special trivalent Zinc-chromate shell plating that is designed to prevent both corrosion and seizure to the cylinder head thus eliminating the need for any thread compounds or lubricants.

NGK recommends only using spark plugs with metal plating on all aluminum head applications to prevent damage to the head and plug. Metal shell plating acts as a “lubricant” which breaks away from the main body of the spark plug during removal, preventing damage to the spark plug and or threads in the cylinder head.

All spark plugs that have a blackened or dull appearance on the metal body offer no protection against seizing or bonding to the cylinder head and so it is with these spark plugs that anti-seize would be required. A spark plug that has a shiny silver appearance on the metal body usually indicates that the plug is manufactured with metal shell plating and therefore will not require anti-seize.
 
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Tip: Don't completely remove the coil pack bolts. Loosen them enough to disengage the threads and they will stay "attached" to the coil pack and not get lost. I used a 3/8 drive universal joint on my 5/8 spark plug socket, then a 3" long extension to the ratchet. (y)
 

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I see this engine has the same difficulties as the 4.7 with regard to the spark plug depth. I bought a 5 inch socket to solve the problem of retrieving a buried socket when I do this maintenance on my Dakota and Durango.

I suspect this is how I'll tackle the job on my Challenger.

Thanks for the great write up. I have been wanting this info.

Sent from my TM800A612R using Tapatalk
 
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I would add just a few more tips. If you have a MOPAR shock tower brace and a MOPAR CAI, you will need a universal joint to use with the extensions as both items limit "straight on" access to some of the plugs. Also, while you won't have to remove it, you will likely need to loosen the CAI mounting box. so it can be moved slightly thereby getting it out of the way.

Most important tip I learned ages ago. I use about a 10" length of vinyl tubing (in the plumbing department at hardware stores - I don't recall the diameter but take a plug with you) when starting the plugs in the threads. Place it over the terminal stud of the plug and turn it to get the plug started. You can actually get the plug most of the way installed and then use the plug socket, extensions, etc. to tighten it. It is 99.9% impossible to ever cross thread a spark plug by starting it like this. It should be 100% impossible; but, someone will always do the impossible. (y)
 
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