Well I am the next victim to the 2012 cylinder head flaw. After coming back from the Dusy I got the dreaded check engine light. Checked the code and it was a #4 cyclinder missfire. It went off a few days later then came back on. Took it to the dealer they checked it out, did a "software update" and said everything was "ok". Few days later it came back on, same code. Then it started idling rough and, maybe my imagination, seemed like there was some power loss as well.
Back to the dealer we go and this time they tell me they have to replace the head.
Kicker is that Chrysler wont let them keep any in stock, has to be special ordered, and could take 7-14 business days!
WTH! Seems like if there is a known issue they would keep some them stocked regionally and replace them as they need more.
Good news I guess is they are fixing it.

I'll update after its fixed.

BTKillerr

 

Just curious, how many miles?

 

Latest mileage I've heard getting the problem is over 28k

 

What is the build date on your JK?

 

Well lets hope I don't have this issue but I got my first oil change today and asked dealer to listen to the motor as I thought I heard a tick and sure enough he said not for sure but it does seem louder on drivers side. Listening from the wheel well it was noticeable on each side.
I am at 3700 miles 2012 2dr jk.
Guess we will see in the near future. Hope not but we will see!

 

I think most failures have been cylinder 2 or 6. Mine was #2 at 12K miles.
Yours is the first that I've read was #4.
In the final analysis, not that big a deal; just a temporary bummer. Hell, they even washed my JKUR and changed the oil when the repair was done!

 

Dont know the build date but got it Nov 2011. I got the first #4 misfire at around 13k, Im at 15k right now. The mechanic told me that it has just been the even number cylinder heads that were having these issues...mine was #4.

BTKillerr

 

So you first noticed a tick on the driver side first?

 

I have. It's clear to me when under the hood.
However the dealer had the tech look and they both said its faint. But is noticeable when listening from the wheel well. He said they have done one wrangler. But mine is faint at the moment and may be nothing. He says usually they settle in about 8k miles before trouble.
He did say they have done a few of the pentastar motors but only one a wrangler

 

Wow. That is exactly the same thing my service advisor told me last week except mine has 8400 miles on it. But he said I'm covered under warranty and if it gets worse they would listen to it again and re-evaluate. I'm in no hurry to have my baby torn apart so I'm waiting for the Check Engine light to come on.