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DIY: Hemi 5.7L Spark Plug Change

237K views 169 replies 71 participants last post by  Arminius 
#1 · (Edited)
Time for the dreaded 16 plug change? Here are a few tips and pictures to get you going... This is not that difficult of a job if you have the right tools and patience.

Notes: This swap should only be performed on a cold engine so plan ahead and do it first thing in the morning or on a weekend. Also make sure to set the gaps on the spark plugs correctly as they are not going to be pre-gapped in the package (OM lists 0.043 in gap). I would also strongly suggest doing the complete engine side at a time as you will save yourself a lot of time in not having to switch tools etc doing it a coil at a time.




Tools and parts required:
- 16 Spark Plugs.
Owners Manual: LZFR5C–11G (Gap 0.043 in [1.09 mm])
Mopar Part Number: SPLZFRC11
- Spark Plug Gap tool
- 3/8 Drive Ratchet
- 3" Long 3/8 Drive Extension
- 3/8 Drive Universal Joint
- 3/8 Drive Torque Wrench
- 5/8 Spark Plug Socket
- 1/4 Drive Ratchet
- 10mm Short socket (1/4 drive)
- 10mm deep socket (1/4 drive)


Here we go...

(1) Remove the engine cover by pulling up firmly at the front edge with both hands and then repeat at the back of the cover.

You will now be looking at the top of the engine and will be able to see the tops of the coil packs down each side of the motor.



(2) Do your best to clean the area around the coil packs to prevent any debris from falling in while changing the plugs. Next unclip each of the 4 wire connectors attached to the coil packs (you can see I have removed the first one in the picture).

(3) Remove the Coil Packs - Start on the passenger side as it is more easily accessed and will get you ready for the more difficult driver side. Using a 1/4" Drive ratchet with a 10mm extension only crack and slightly loosen all 8 of the 10MM Hex bolts show above. Once they have been cracked you should be able to spin them the rest of the way using just your fingers. These bolts do not need to be completely removed in order to take out the coil packs so only loosen them about half way and the coil pack will come free. While removed I kept the coil packs in the correct order so they all went back in the same cyl they came out of. I dont believe this is necissary but did it anyways.

Here is a shot of the first coil pack once removed. The arms are flexible to make them easier to install/remove in the small space:



(3) Once all coil packs have been removed you can now crack all the spark plugs. I found that a 3/8 Drive ratchet with a 3" long extension, then a universal joint, then the spark plug socket was just the right length to be able to get to all 16 plugs without having to change extension configuration. (See first pic) Once they are cracked I found it fastest to remove the ratchet and loosen them the rest of the way by spinning the extension and socket by hand. If you have a good spark plug socket with a magnet you can skip the next step...

(4) I had a crappy spark plug socket with rubber boot that comes out every time so I used a telescoping magnetic tool to grab the old plugs and pull them out from the deep:



*Some people prefer to apply dielectric grease to parts of the plug and wire connection but there was plenty still left on there so I didnt bother. (btw I was quoted $35 for a new tube at the dealer :eek:)

(5) Using the spark plug socket insert the newly gapped plugs and thread them in carefully by hand to avoid stripping. Once all 8 plugs are installed finger tight use a torque wrench set at 12-14 ft/lbs to properly snug each of the plugs down. DO NOT EXCEED 14 lbs.

(6) Reinstall each of the 4 coil packs and pressing the stems down onto the plugs. Next go back to your 1/4" ratchet and 10mm socket to tighten all of the 10mm Hex bolts until the coils are snug and secure back in place.

(7) Re-attach each of the 4 wire harness clips

(8) Repeat steps 1-7 for the driver side. It is a little tighter to work with because of the intake hardware etc in the way but overall everything is pretty easy to access and the proceedure is the same as the passenger side.

(9) Reinstall engine cover

(9) Finally I disconnected the negative battery terminal for 5min to reset the ecu/tcu etc. This is also not required but I felt it was worth the minimal effort.

and that's it!... Fire it up and make sure everything is nice and smooth!

Impressions: I'm not going to lie, I was not impressed about having to change 16 plugs after 30k but am glad I did. I had recently been noticing a rougher than normal idle in the morning and at some stop lights but that is completely gone with the install of the new plugs. Also the engine without a doubt feels more responsive and has restored that like new power again.

Save your hard earned $$$ and DIY:thumbsup:

.
 
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#67 · (Edited)
If you are going to install NGK 100 THOUSAND MILE plugs into your aluminum heads YOU BETTER use a dab of antiseize on them if you want to remove them one day!

I don't care what NGK recommends. My OEM NGK plugs were replaced at 2 years of service and those same plugs that NGK claimed to be "self-lubricating and corrosion resistant" were already beginning to corrode on the threads. :eek:

If your concerned about proper plug grounding use a hi heat copper antiseize, just a dab, and always install using a good torque wrench.

The galvanic corrosion that will occur with two dissimilar metals over thousands of heat cycles and thousands of miles will seize your plugs into your aluminum heads. To those who don't believe get back to us in another 100K miles when you need to replace your "self-lubricating and corrosion resistant" NGK plugs! :slapfight:

Wasn't this already covered in this thread??
 
#71 ·
My dealer confirmed the iridium plugs would work in my 2012hemi... And they do.. All 200 bucks worth! No issues at all in about 1000 miles.

Dealer BS is everywhere...

I bet most siezed plugs were originally over torqued.. ?? I don't use antisieze, I use an Armstrong torque wrench.
 
#74 · (Edited)
604,

Thanks for the write up. With my dad's help, finished in just under 2 hours on our first 16 spark plug change on my 2012 5.7L WK2. Was just right at 30,000 miles. I got the 16 spark plugs from justforjeeps for $60 plus shipping so $71 total. Gap was perfect on all 16. Little to no wear on the 16 replaced plugs.
 
#76 ·
I pulled the plugs on my '14 WK2 Summit 4x4 5.7 and the stock plugs are NGK IR plugs. Looks like they should be good for a lot more than 30k?

Thoughts?

I bought copper plugs thinking thats what I had, but now that I know they are iridium with platinum cores, I am not sure if i should waste the time and/or money.
 
#79 · (Edited)
Planning on tackling this on Saturday. Going with the mopar copper plugs since they are a lot cheaper than the NGK IR plugs and I doubt I'll have the jeep for another 30k miles. I guess my main questions after reading this thread are:

1. I don't need to use antisieze since the copper plugs are pulled every 30k miles, correct?
2. The correct torque specs are 18-21ft/lbs for the copper plugs, not the initially stated 13ft/lbs?
3. The plugs listed on justfor jeeps says they are nickel plugs, I thought oem was copper?
http://www.justforjeeps.com/095hesppl.html
The part number is different too. OEM is SPLZFRC11 versus SPLZFR5C11 on justforjeeps.

Thanks.
 
#80 ·
Planning on tackling this on Saturday. Going with the mopar copper plugs since they are a lot cheaper than the NGK IR plugs and I doubt I'll have the jeep for another 30k miles. I guess my main questions after reading this thread are:

1. I don't need to use antisieze since the copper plugs are pulled every 30k miles, correct?
2. The correct torque specs are 18-21ft/lbs for the copper plugs, not the initially stated 13ft/lbs?

Thanks.
I checked with my dealer (2012 5.7l hemi GC) and the torque spec is 18-21ft/lbs. I have done one change at 46,000 miles with plugs showing little wear with no decrease in mileage or performance before changing. I replaced with NGK OEM plugs and now at 65,000 have seen no decrease in mileage or performance. Unless I see a mileage and/or performance change I will not change again until 100K and will use copper core plugs. As applying anti-seize only takes a few minutes, I did use it for my first change and will use it for subsequent changes.
 
#83 ·
OK I did the swap today and found the connectors are just tight...a little pulling and they came right off. All in all not too bad but the plugs that came out looked very good with no corrosion, pitting, or arc damage. It seemed like a waste to throw them away.
I did notice the GC seems to run smoother though so it seems worth it for sure.
 
#84 · (Edited)
I have a 2011 5.7 Hemi Limited Grand Cherokee. I asked my dealer if they would put the NGK IR plugs in instead of the copper ones. They insisted that they had changed the head design in the newer Hemis and if you put the IR plugs in them it will burn up the cylinder heads. Said the IR gets way hotter. Sounds like bull but I did not want to risk it so I had them put the copper ones in.

What yall think?
 
#85 · (Edited)
I have a 2011 5.7 Hemi Limited Grand Cherokee. I asked my dealer if they would put the NGK IR plugs in instead of the copper ones. They insisted that they had changed the head design in the newer Hemis and if you put the IR plugs in them it will burn up the cylinder heads. Said the IR gets way hotter. Sounds like bull but I did not want to risk it so I had them put the copper ones in.

What yall think?
I think you have a service advisor at yet another Jeep Dealership that truly has no idea what he is talking about!! IR plugs will burn up the cylinder heads?? How? Why? Maybe he's stuck in a time warp and is referring to pre 2009 Hemi's.... but I'm pretty sure none of those old hemi's made it into 2011+ WK2's.

These IR plugs have only one listed application from NGK........ that is a Chrysler 5.7L hemi. They are OEM Mopar parts with the correct heat range as spec'ed by Chrysler to NGK for 5.7 L hemi V8's.

Changed the head design in the new Hemi's??
When did that happen.... from 2013 to 2014 models when Chrysler started installing them as OEM parts?? Really?

The IR plugs were first installed in Chrysler police package vehicles for 100K miles maintenance intervals. Chrysler made them OEM parts for all 2014 5.7L V8's to keep up with other manufacturers 100K miles maintenance schedule's.
These IR plugs are just a better quality longer life OEM NGK 100K mi plug vs. the OEM NGK 30K mi copper plugs.
 
#94 ·
Well coming up on my 3rd Plug change, The past 2 changes i dont think that they were ready to be changed. but the Warranty says Every 30000mi and dont want any issues with the $2300 Mixi Care extended warranty :(
 
#95 ·
Thanks for an informative post. No time to read all 8 pages. Doing my plugs today and just going with stock Champion 446 plugs. Should be fine. Bought my 09 Commander Overland with 5.7 Hemi in Dec last year. 127K miles, no service history. Got a code for misfire in #3 cylinder and figured it could use some new plugs anyway. :thumbsup:
 
#96 · (Edited)
Thanks for an informative post. No time to read all 8 pages. Doing my plugs today and just going with stock Champion 446 plugs. Should be fine. Bought my 09 Commander Overland with 5.7 Hemi in Dec last year. 127K miles, no service history. Got a code for misfire in #3 cylinder and figured it could use some new plugs anyway. 👍
Your in the wrong forum for an '09 Commander w/a 5.7 Hemi engine!
A lot of the plug discussion in this thread doesn't apply to you......

Jeep went to OEM copper plugs for all 2011 and up WK2 Hemi's manufactured by NGK and NGK Iridium plugs are OEM for all 2014 and up Hemi equipped WK2's.
 
#97 ·
I don't see that you have a forum for the Commander in Platforms. Either way, the how to helped a lot in how to do it. I have read discussions all over the place about what plugs to use and in the end decided to just get the stock Champion plugs. Interestingly enough, the engine had NGK's in it. More troubling, though was the fact that cylinders 3 & 4 plugs were barely over hand tight. new plugs in, torqued to spec with anti seize, running great with no more CEL.
 
#100 ·
They don't look that bad to me. Of course, I can't see how much electrode wear there is.

Dan
 
#102 ·
I don't understand the questioning on the use of anti seize on plug threads? Why not? There is no downside to using it. Most auto parts stores will throw in a couple of those small, tear open, disposable tubes for free. At worst Permatex Copper C-5A, (the same thing Glock puts on the slides of it's pistols), is under $20 bucks for a small can that will last a lifetime. I've NEVER seen a thread damaged using that stuff. Even on shotgun chokes that have been left in for years. They endure way more carbon and fouling than any spark plug screwed into a modern engine.
 
#103 · (Edited)
Yes!! Of course if you've read my posts in the thread, you'll see I couldn't agree more. :thumbsup:
The copper anti-seize you mentioned is an excellent product as is the choke tube analogy. I do all my own work and if I still own this Jeep after 100k mi. I'm sure I'll be very glad I applied some anti-seize to the plugs when I have to change them again.
 
#107 ·
This DIY write up was exactly what I needed!!! My 2014 GC Summit 5.7 HEMI had NGK Iridiums in it and the MOPAR part from the dealer were NGK Iridium replacements. I will post a pic soon. I have 42,000 hard miles on her, local driving but 5 (fast) road trips NY to Fl, Mom n Dad and Diving in Keys.

Huge improvement, esp with all changes, new PCV, new fluid in Front n Rear diff and KnN drop in filter.
 
#108 ·
THANKS FOR THE GUIDE!!!! I have everything I need to do my 2013 JGC 5.7L this evening except a gapper (will have to pick one up on the way home). I'm currently just shy of 40k miles on the GC. Curious how bad they will look.
 
#109 ·
l

Curious about the plugs too as I have a 2013 V8 too with 50+K on them.

Dan
 
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