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Discussion Starter · #1 ·
Hello guys, new to forum and looking forward to learn from your experience :)

My tuned 2017 SRT is doing pretty well no complains, just last month was doing regular service and decided to replace all plugs, i went with Autolite XP6043

noticed the NGK i removed had few different gaps (photo with 3 plugs) and was wondering WTH but thought maybe installer gapped them wrong or dropped plugs

then i cleaned up coils and added some silicone grease then installed all new plugs and checked one by one for correct gap, few weeks later i got a code misfire Cylinder 7

bulled plugs out to find both of them have zero gap (photo with 2 plugs) now i\m worried how they got closed ??

I drive it hard sometimes and recently i put it on dyno with several WOT trials and no issues happened, it gets really hot here where i live but engine temps are not exceeding 110-115 C, Intake air temp is what worries me as it gets rally high sometimes specially in traffic.

so i got myself cheap endoscope camera to try to see is something inside the cylinder hitting plugs, and i saw lots of scratches and dents on cylinder as you see in below photo, but couldn't lower cylinder all way down to get complete picture of cylinder, i insert a magnet inside nothing came out, blew air several times nothing came out also.

so I Installed correctly gapped 2 plug and reset codes and fire it up and it works just fine.

drove it to work and nothing abnormal at all, of course very gentle driving.

what you guys think I'm against now, appreciate your inputs 馃

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JGC Srt8 2014
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Hi there.
I am no big specialist and do not want to frighten you, but I'd say that if there scratches on piston surface - smth was scretching it ))). That means that smth might have been broken (((.
I'd suggest you go to a good engine technician, who would have a professional endoscope and who could check all pistons with it , especially those where the scretches are.
I myself had similar issue. It appeared that one piston was broken, had to replace it. Hope it is not the case for you, touch wood..

Btw, do you have any oil consumption? Cause when I was driving with broken piston - my oil consumption was quite huge. After replacing - it got down to almost zero.

Good luck ,man!
 

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Hope this helps,

Detonation will close the spark gap.
I doubt the engine is hurt otherwise the new plugs would have had their gaps closed as well once you ran it.
You said the car had a tuner, was it just a canned tune or was it a custom one?
If it was a custom one the tuner may have dialed in too much spark advance.
If it was a canned Diablo tune then it's possible the original owner dialed in more timing as well.
Either of those circumstances can cause detonation.

Are you running premium fuel? Did you bounce off the rev limiter or hear any detonation?
too much timing ignites the fuel/air mixture too soon so the remaining fuel spontaneously ignites after initial combustion (detonation). This causes a major short term pressure spike in the cylinder that can cause damage if left unresolved. Bent spark plugs are an indicator of long term detonation. Broken ring lands are a possibility in extreme cases.

Hitting the rev limiter has nothing to do with detonation. It is s safeguard and won't hurt anything. I hit it many times at the track with no damage. It's the guys who raise the limiter that have problems. I've always left it alone.



Bent Spark Plugs in my Hemi | Page 2 | DodgeTalk Forum
 

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Discussion Starter · #4 ·
Hi there.
I am no big specialist and do not want to frighten you, but I'd say that if there scratches on piston surface - smth was scretching it ))). That means that smth might have been broken (((.
I'd suggest you go to a good engine technician, who would have a professional endoscope and who could check all pistons with it , especially those where the scretches are.
I myself had similar issue. It appeared that one piston was broken, had to replace it. Hope it is not the case for you, touch wood..

Btw, do you have any oil consumption? Cause when I was driving with broken piston - my oil consumption was quite huge. After replacing - it got down to almost zero.

Good luck ,man!
Thank you for prompt reply,

Exactly i feel that's lot of scratches on cylinder, and wonder what can cause it ? I had zero oil consumption earlier now you mentioned it will keep checking and see.

Did you know how your piston broke ? is it boosted or NA ? tuned ?

will check if any engine tech around knows how to properly endoscope and check
 

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Discussion Starter · #5 ·
Hope this helps,

Detonation will close the spark gap.
I doubt the engine is hurt otherwise the new plugs would have had their gaps closed as well once you ran it.
You said the car had a tuner, was it just a canned tune or was it a custom one?
If it was a custom one the tuner may have dialed in too much spark advance.
If it was a canned Diablo tune then it's possible the original owner dialed in more timing as well.
Either of those circumstances can cause detonation.

Are you running premium fuel? Did you bounce off the rev limiter or hear any detonation?
too much timing ignites the fuel/air mixture too soon so the remaining fuel spontaneously ignites after initial combustion (detonation). This causes a major short term pressure spike in the cylinder that can cause damage if left unresolved. Bent spark plugs are an indicator of long term detonation. Broken ring lands are a possibility in extreme cases.

Hitting the rev limiter has nothing to do with detonation. It is s safeguard and won't hurt anything. I hit it many times at the track with no damage. It's the guys who raise the limiter that have problems. I've always left it alone.



Bent Spark Plugs in my Hemi | Page 2 | DodgeTalk Forum
Thank you :)
I came across this post while googling this issue

so far new plugs running fine, but i didn't go WOT so far
tune is custom using HPtuners, timing is only few degrees above factory at WOT
using the best fuel available around here
maybe intake temperature too high causing detonation also ?

if piston ring lands broken will engine run fine still ? what symptoms i should observe ?
 

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JGC Srt8 2014
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Thank you :)
I came across this post while googling this issue

so far new plugs running fine, but i didn't go WOT so far
tune is custom using HPtuners, timing is only few degrees above factory at WOT
using the best fuel available around here
maybe intake temperature too high causing detonation also ?

if piston ring lands broken will engine run fine still ? what symptoms i should observe ?
In my case with a piston broken the engine was absolutely stable, unless the oil consumption - nothing unusual . No check engine, anything.
Mine is supercharged. Just went to check why oil consumption increased.
 

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Possibly a piece of the ring land broke off and bounced around. Turn the engine on and open the dipstick, do you have excessive blowby? Also check oil level before and after at least 500km, do you have increased oil consumption?
Another possibility is a broken valve seat but I think it's less likely.
 

BlaBlaBla
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I鈥檓 no expert but I鈥檝e seen this more than once. I鈥檒l bet one of the cylinders is number seven.
Oil soaked closed plugs coupled with beat up pistons equal ring failure. The new plugs didn鈥檛 close because that piece of ring has moved on to do more damage elsewhere.


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Discussion Starter · #9 ·
I鈥檓 no expert but I鈥檝e seen this more than once. I鈥檒l bet one of the cylinders is number seven.
Oil soaked closed plugs coupled with beat up pistons equal ring failure. The new plugs didn鈥檛 close because that piece of ring has moved on to do more damage elsewhere.


Sent from my iPhone using Tapatalk
Thank you for input ,

I thought broken piece went out exhaust valve and out through exhaust since i have no cats ??
where else can broken piece move to ?
 

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Discussion Starter · #10 ·
Just checked for blowby from dipstick and i found non at all, i tried to feel with my hand then got a piece of paper to see if it moves but nothing at all

now not sure if nothing at all is a good or bad sign ??
 

BlaBlaBla
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Thank you for input ,

I thought broken piece went out exhaust valve and out through exhaust since i have no cats ??
where else can broken piece move to ?
You could have pieces in your oil pan possibly causing damage to the lower end.
Continuing to drive it will only prolong the inevitable.


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Discussion Starter · #13 ·
You could have pieces in your oil pan possibly causing damage to the lower end.
Continuing to drive it will only prolong the inevitable.


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Not sure how broken pieces of piston ring land can reach oil ban ??
I usually check oil every oil change for any metal shavings, having in mind the famous MDS lifters issue and i have also magnet drain plug and so far no metals in oil at all
I'm planning to remove plugs again in #7 and check and hopefully can see better view of piston with endoscope

other than that anything you recommend to do ? i know best is to remove heads and check but before that any DIY things i can check ??

appreciate your support :)
 

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Any update on this one? While waiting, some points:
  • detonation will not bend spark plug electrodes.
  • metal bits in oil pan will not do damage, unless the oil filter is bust. Unfortunately usually metal pieces found in oil also mean there is metal grit in oil, that will over time ruin bearings and other moving parts
There are long scratches on piston tops, thats really weird. The scratches are actually imprints of some pieces that ended up in the cylinder. Most likely this very same piece bent the electrode, broke into smaller bits as they were bouncing around, and eventually evacuated via exhaust.

At least the head will have to come off. With good luck you might be able to change the piston in situ. Don't know if this is possible on a SRT GC.
 
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