Results 1 to 10 of 10
  1. #1
    Join Date
    Oct 2018
    Posts
    4
    Post Thanks / Like

    What's going on with sparkplugs for our Hemi?

    Hello. I am new here, and owner of a 2007 (build in 2005) 300C AWD Hemi 5.7 Touring.
    I bought the car with low miles (50K), first owner.
    Changed a lot of sensors, just as test. And every sensor did something positive.
    So in my case, don't fix it till it's broke, did not work out

    At 55K miles sparkplugs were changed to NGK
    Type: LZTR4A-11
    Stock No.: 5444
    But, i got very quickly misfires.
    Now, new plugs, same as above, and misfires are almost gone. So we are on the right track.
    Could it be that these plugs are not suitable for my Hemi?

    I read a lot about several brands of plugs, Platinum, Iridium. Etc etc.
    Also all kind of different opinions. Maybe this is due to the coilpacks on that particular car?
    I just changed mine out for NGK coil packs.
    Platinum seems to be a nog go, but Iridium plugs from Champion, Autolite or NGK, would this work?

    Thanks for helping!

  2. #2
    Join Date
    May 2010
    Location
    MD
    Posts
    1,049
    Post Thanks / Like
    Quote Originally Posted by Bernard1975 View Post
    Hello. I am new here, and owner of a 2007 (build in 2005) 300C AWD Hemi 5.7 Touring.
    I bought the car with low miles (50K), first owner.
    Changed a lot of sensors, just as test. And every sensor did something positive.
    So in my case, don't fix it till it's broke, did not work out

    At 55K miles sparkplugs were changed to NGK
    Type: LZTR4A-11
    Stock No.: 5444
    But, i got very quickly misfires.
    Now, new plugs, same as above, and misfires are almost gone. So we are on the right track.
    Could it be that these plugs are not suitable for my Hemi?

    I read a lot about several brands of plugs, Platinum, Iridium. Etc etc.
    Also all kind of different opinions. Maybe this is due to the coilpacks on that particular car?
    I just changed mine out for NGK coil packs.
    Platinum seems to be a nog go, but Iridium plugs from Champion, Autolite or NGK, would this work?

    Thanks for helping!
    Those years you need to stick with the OEM style copper cores, SPRE14MCC4. They don't really seem to like platinum or iridium, etc.
    03 Hemi Ram, 05 Magnum R/T, 06 Charger R/T (RIP)

  3. #3
    Join Date
    Mar 2009
    Location
    Edmonds, WA
    Posts
    6,790
    Post Thanks / Like
    Ive used platinum on both my Magnums for 80k miles each time. Put Iridium in about 10k miles ago and never had misfire problems. Should make sure gap is correct and use dielectric grease into boots. Are you saying you changed from stock coil packs to NGK coil packs? That may be issue.
    I have only heard of misfire issues from the double or triple electrode strap plug types

    Sent from my SM-G925V using Scat Pack Forums mobile app
    2008 Magnum BB R/T Hemi Registry # 1584 PPP Stage 2 Cam, JBA Shorty Headers, JBA High Flow cats, Heartthrob Exhaust, Eagle Intake, LMI Intake, MTCM, Blue Tops, ProTorque Converter, SRT Rear, Techo Strut Brace, lowered, Tuned by Diablotoona SOLD--2005 Mineral Gray AWD Hemi Registry # 1154

    Quote Originally Posted by Hemissary View Post
    For the work being performed, length is far more important than diameter :^)

  4. #4
    Join Date
    Nov 2014
    Posts
    2,193
    Post Thanks / Like
    Stock coppers are best unless you have a reason to change them (more powah) to a colder plug.


    Sent from my iPhone using Tapatalk

  5. #5
    Join Date
    Sep 2018
    Location
    SF Bay Area
    Posts
    58
    Post Thanks / Like
    I installed champion 3570 platinum plugs about 3k miles ago. My 06 RT magnum has 106k miles. Its early, but no issues at all so far.
    2006 Dodge Magnum R/T: K&N CAI, custom grill, 180 degree t-stat, Diablo Trinity T1000, 300 SRT rims, spec-d headlights, backup camera, debadged, 2 car seats.

  6. #6
    Join Date
    Oct 2018
    Posts
    4
    Post Thanks / Like
    I am very happy with the new NGK coil packs, engine runs better with more power.
    Now with the new NGK plugs i noticed that it is not idling as rough and now below 1500 rpm a few misifres if i step on it without trans shifting back.
    So it is better, but still not ok.
    And because it is reacting like this, i am afraid that NGK is not working in my car. Same as all aftermarket sensors, it doesn't work right in my car....
    I will try Champion and let you guys know how it went.

  7. #7
    Join Date
    Mar 2010
    Location
    Sedalia, Missouri
    Posts
    404
    Post Thanks / Like
    There was a Starcase which talks about the intermittent engine operation. I tried to post the PDF but could not. Maybe someone else can, or can find in with a search.

    Case Number: S1218000002
    Release Date: 01-27-2012
    Symptom/Vehicle Issue: Intermittent Engine Die Out

    The end result is to use recommended OEM parts.
    It seems that some of the platinum and other long life plugs randomly generate RFI which interferes with computer operation. This was solved in later years and the introduction of the long life plugs in the Hemi.

    Good luck



  8. #8
    Join Date
    Oct 2018
    Posts
    4
    Post Thanks / Like
    I was in doubt to use Denso or Autolite Iridium plugs, i drive 40K each year......but some have luck and some don't.
    I use the Sparky ignition cables, maybe the longer ignition wires were also a problem with Iridium plugs....

  9. #9
    Join Date
    Sep 2009
    Location
    Bainsville Ontario
    Posts
    6,174
    Post Thanks / Like
    I've been using NGK Iridium plugs for the past 5 years and 110k kilometers. They are stil working fine but they will be changed when the car goes away for the winter. Getting around 10.7 l/100km.

    inTune 91 CAI, 180 stat, BB 6dB reso delete,Tranzformer, MDS indicator, ESP/BAS switch. Wire mesh grille, smoked and flashing side markers, 9005 2400k 65W fogs, rear fogs, debadged and demolded, 245/45/20 and 295/40/20 Continental DW's on 9"/10" F/R Viper Replicas, BCR Coilovers, Drake strut brace. Interior accent LED 's. 55/35 tint, BT catch can. LED interior lighting. BT bling, front parking sensors. Rear seat heaters. Color matched tails "MoPar" puddle lights. Custom front lip.
    MyGig 730N, Pyle 9.2" screen, iPod, front and rear cams.

  10. #10
    Join Date
    Oct 2018
    Posts
    4
    Post Thanks / Like
    Quote Originally Posted by Steve65301 View Post
    There was a Starcase which talks about the intermittent engine operation. I tried to post the PDF but could not. Maybe someone else can, or can find in with a search.

    Case Number: S1218000002
    Release Date: 01-27-2012
    Symptom/Vehicle Issue: Intermittent Engine Die Out

    The end result is to use recommended OEM parts.
    It seems that some of the platinum and other long life plugs randomly generate RFI which interferes with computer operation. This was solved in later years and the introduction of the long life plugs in the Hemi.

    Good luck
    That's why i stick with OEM plugs...
    I used my new MaxiECU scanner, i notied that when the engine runs rough at idle, the sensors voltage is also fluctuating a little bit.
    Like the Throttle position sensor, but i also see the spark advance going from 6-16.
    When i rev it for a few minutes to 1500RPM and let it go back to idle, voltage is stable again.
    Can the new NGK standard plugs give me these trouble?

    I ordered new Champion 570 plugs with the black top

Tags for this Thread

Share This Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •