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Discussion Starter #1 (Edited)
4.7 - V8 Spark Plug change Write-up

i don't know if anyone has written a write up on changing spark-plugs on the 4.7L commander. but since i'm pretty mechanically inclined and CHEAP i don't pay anyone to work on my vehicles.

Tools needed for the Job:

10mm socket
5/8" spark plug socket tool
short 3/8" extension
long 3/8" extension
3/8" socket driver
Flat head screw driver

Time needed: about an hour

Parts needed: 8 spark plugs of your choice.

My commander only has 26K on it. but since i bought it used i decided what the hell, i might as well change the plugs. they weren't in bad shape, but they were champion spark plugs and i really hate those.

i picked up 8 NGK V-Power spark plugs for $22. I have been using this brand in my vehicles for years.

i also noticed when i pulled my old spark plugs the gap was not right. they are supposed to be gapped a .044". my old plugs were gapped at .038".


Step 1.

remove the intake pipe and intake resonator. there are 3 clamps holding all the intake piping together use the flathead screw driver to loosen these. and there are 2 10mm bolts holding the resonator to the intake. unbolt and set somewhere out of the way.




here are pictures of the 2 10mm nuts holding the resonator in place. also don't forget to unhook the air temp sensor the the passenger side of the motor. you can see it on the bottom picture.

 

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Discussion Starter #3
Step 2.

there are 8 coils held in place with a 10mm nut. remove the 8 nuts with the 10mm socket and driver you may need the extensions for this, and put somewhere safe.

Step 3.

unhook the wires connected to each coil.

pictures for for steps 2-3



this is the coil there are 8 of these



Step 4.

remove the coil on the spark plug. i kept mine in order of where they came from. i'm not sure if it makes any difference or not. but i didn't want to find out the hard way. use the extension and 5/8" spark plug socket for this step
 

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Discussion Starter #4
Step 5.

gap your spark plug to .044". remove the old spark plugs and install the new ones.



for comparison. old plugs verses new plugs.





Step 6.

reverse the process and enjoy.
 

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Discussion Starter #5
well, i guess no one has anything to say.

i have been driving it with the new plugs. i must say i am very impressed with these NGK's. my mileage has gone from 16.5 mpg up to 19.5.

when i'm cruising at 70 i get between 20 and 22 now.

i also added a Trueflow air filter about 1 month ago.

the commander does not down shift as much on hills anymore. i'm very happy!
 

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I don't have the 4.7L, but do appreciate you taking the time to document this. I do plan on going with Iridium plugs when it's time to change, but it will be a while before that happens because I just went past 10,000 miles. Also, the Iridium plugs will be very expensive since I will need 16.
 

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Discussion Starter #8
they said on the 4.7 you do not need to run platinum or irridium. its just a waste on that motor. i would imagine it would be the same with the 3.7L.

since the 5.7 is a higher compression motor i would imagine the more expensive plugs would be better.
 

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Nice job on the write up. With the performance gains you recieved - Will that eventually go away with the wear of the plugs or is that a gain because of better quality and proper gap?
 

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Excellent writ eup. I am surprised at the MPG improvement if with the gap tolerance difference. Are the new plugs a bit hotter or did you stay the same? Your old plugs didn't look too bad.
 

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Discussion Starter #11
better brand of plugs.

i think they are the same temp plugs. i just got replacements.

i hate champion plugs. i think they are crap.. i'm a engine performance guy. i've been running NGK for years in my japanese engines. i thought i'd try them in the jeep. them made a big difference. i'm not sure if the gap makes a big difference. but, there is a bigger spark now. so the fuel is burning more efficiently.

the engine has much more power. i got the jeep up to 105 passing cars the other day. i couldn't believe i was going that fast. it seems to have a lot better power.

i can't wait to work on the exhaust!
 

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Hey everyone, the 4.7 is different from the Hemi, you need 16 plugs on the Hemi plus it is torque specific (13 ftlbs). So you need wrench. I put in th champion iridiums (9043) and love 'em! I wold recommend signing up fo alldatadiy.com it is the best site for everything you need to know about your vehicle ad how to maintain it. Here is the info from all data:
Notes
Spark Plug

Gap
Spark Plug Gap 1.14 mm (0.045 in.)

Torque
Spark Plug Torque 18 Nm (+/- 3) 13 lb. ft (+/- 2)

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Removal and Installation

SPARK PLUG

REMOVAL
Each individual spark plug is located under each ignition coil. Each individual ignition coil must be removed to gain access to each spark plug.


Remove necessary air filter tubing at throttle body.
Prior to removing ignition coil, spray compressed air around coil base at cylinder head.
Prior to removing spark plug, spray compressed air into cylinder head opening. This will help prevent foreign material from entering combustion chamber.
Remove spark plug from cylinder head using a quality socket with a rubber or foam insert. Also check condition of ignition coil O-ring and replace as necessary.
Inspect spark plug condition.
INSTALLATION

NOTE: The 4.7L is equipped with copper core ground electrode spark plugs. They must be replaced with the same type/number spark plug as the original. If another spark plug is substituted, pre-ignition will result.

Special care should be taken when installing spark plugs into the cylinder head spark plug wells. Be sure the plugs do not drop into the plug wells as electrodes can be damaged.

Always tighten spark plugs to the specified torque. Over tightening can cause distortion resulting in a change in the spark plug gap or a cracked porcelain insulator.



Start the spark plug into the cylinder head by hand to avoid cross threading.
Tighten spark plugs to 27 N.m (20 ft.lbs.) . 3.7L & 4.7L.
The 5.7L is equipped with torque critical design spark plugs. Do not exceed 15 ft. lbs. torque. Tighten spark plugs to 18 N.m (13 ft.lbs) . NOTE: 5.7L does not use an o-ring
Before installing ignition coil(s), check condition of coil O-ring and replace as necessary. To aid in coil installation, apply silicone to coil O-ring.
Install ignition coil(s).
 

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Discussion Starter #13
i never use a torque wrench. i do it by feel. i go till its hand tight and then turn about 1/4 turn more. i've never had a problem with that method. i have never found a torque wrench that works really good at such a low reading.

mind you i have been working on my cars for about 15 years now.

i tried to use a torgue wrench to tighten the bolts on a new clutch kit i was installing on my toyota supra motor. i ended up stripping the threads on one bolt. it was supposed to be torqued to 20#.
 

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Craftsmen make a really good wrench, it is like $99 but keep an eye out for sales. Remember not everyone in this forum has your touch after 15 years of working on cars. Thats a good amount of experience and from the looks of it on here a lot of us haven't been working on cars that long.
 

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curleycommander said:
Craftsmen make a really good wrench, it is like $99 but keep an eye out for sales. Remember not everyone in this forum has your touch after 15 years of working on cars. Thats a good amount of experience and from the looks of it on here a lot of us haven't been working on cars that long.
You got that right! I envy how good some of you guys are - I am just trying to learn from you... I may be looking into some new plugs for my 3.7 with they way you guys are talking up the performance. Thanks!

And whats the hype with these iridium plugs, are they just hotter?
 

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Personally, I don't think you'll find a better plug for a mopar engine than a Champion. The NGK are good plugs, but no better in a Mopar than the cheapy Champions. Been bleeding Mopar for 30+ years, Champion work the best in them.
 

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Has anyone tried the NGK G-power platinum plugs ZFR6FGP. They cost and average of .20-.40 more than the V-power plugs.
 

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Dont forget Dilectric grease and Anti seaze (<--spelling?) Grease too.
 

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Command This. said:
You got that right! I envy how good some of you guys are - I am just trying to learn from you... I may be looking into some new plugs for my 3.7 with they way you guys are talking up the performance. Thanks!

And whats the hype with these iridium plugs, are they just hotter?
I would go for this one...Pulstar, quite expensive, but probably worth the performance and fuel economy improvement.

http://www.pulstarplug.com/index.html
 
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