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2012 JKU Rubi Check Engine Light - Misfire Cylinder 6

72K views 160 replies 93 participants last post by  JKwrangler12 
#1 ·
A check engine light illuminated on my 2012 Rubi JKU (10,800 miles) this past Sunday. The code indicated "misfire cylinder 6". Took it to Maxwell Jeep in Austin Monday morning and got a call Monday afternoon saying it was ready to be picked up. The service rep said they flashed the computer with a program update and that the problem was solved.

I picked it up this morning and drove it for about 20 miles before the check engine light illuminated once again. Took it back to the dealer and received a call this afternoon saying that they were going to have to go into the engine to find the problem and should know something by tomorrow afternoon.

Has anyone else had a similar problem?
 
#3 ·
My New 2012 wrangler unlimited rubicon wth 12,347 miles on it had the same problem. The dealer flashed the computer and the same thing happened to me...light came back on a day later. It is now sitting at the dealership getting a new head!!! Sound like you and I are having the same problem as the other people in the "ticking jeep" thread. My rubicon was delivered in late August of 2011.
 
#5 ·
2012 Jeep Wrangler Check Engine Light at 10k miles.

I have a 2012 Jeep Wrangler Unlimited sport. I took it to the dealer ship two weeks ago and they flashed the computer. I drove off the dealer lot and five minutes later the light came back on. I took it back in and they are telling me that they need to order the cyl heads and replace them. I bought my jeep in Oct 2011. I had 10500 miles on the engine when the light came on.
 
#8 ·
1. A CPU update will not solve a CEL. OBDII regulations state that CEL's are for emissions related malfunctions. Computers do not get old and nothing changed on your car to warrant an "update". It is dealer BS. They just clear the computer codes and hope for the best (if the vehicle is running well). For them, it's worth it and personally a strategy I agree with. A misfire may not mean all hell is about to break loose. It may never happen again. If it comes back on, then the dealer will actually investigate a bad part.

2. The problem does not sound widespread. How many 2012's sold. I see 5 posts.
 
#16 ·
Most large threads have the same people posting, so number of posts is low.
So lets say 500 posts, 75% being non-repeat posts (which I think is generous). That 375 people.

How many 2012 Wrangler have been sold. Maybe 40,000 (they sold like 9300 in February)?

Now how many of the 375 posts are about the same problem. Lets say 80% (which I think is also generous).

So, less than 1%. That is not common. Its common on the internet. It is not a "common" issue. It sucks when it happens to you, but that doesn't make it any more common.
 
#17 ·
I hope you're right, but in a few conversations with people owning 2012 Wranglers, and literally just getting off the phone with a Chrysler tech buddy this problem is gaining steam.
 
#18 ·
Jurhip said:
Most large threads have the same people posting, so number of posts is low.
So lets say 500 posts, 75% being non-repeat posts (which I think is generous). That 375 people.

How many 2012 Wrangler have been sold. Maybe 40,000 (they sold like 9300 in February)?

Now how many of the 375 posts are about the same problem. Lets say 80% (which I think is also generous).

So, less than 1%. That is not common. Its common on the internet. It is not a "common" issue. It sucks when it happens to you, but that doesn't make it any more common.
The problem is common not a common problem.., wait does that make sense? :hide:
 
#19 ·
You do understand how the internet can "magnify" the prevalence of any issue. Only people that tend to have problems post on these, hence they are "common" on the internet, but not common in real life.

I am not saying there isn't an issue. I just don't think it is a common as these forums make it seem.
 
#23 ·
2012 Sahara CEL-"misfire cylinder 2"

My Jeep purchased in October 2011 began this malfunction at about 12k miles. I have cleared the codes and like others, the CEL promptly reappeared within a few miles. There seems to be a power loss as well as a rougher idle since this issue presented itself.
 
#25 ·
I read somewhere that Chrysler was celebrating the production of their millionth Pentastar engine. That is a lot of engines. Are their actually one million Chrysler products on the road with this engine? Or are there a lot of these engines sitting in stock waiting to be installed? Do they fix the engines sitting in stock, or do the install then hoping not all of them are bad? Just wondering that's all. It took Ford and GM years to resolve production issues with a few of their engines, is Chrysler any different?
 
#27 ·
New Heads for my 2012 JKU Sahara

Well...I am sad to report the following. My 2012 JKU Sahara (currently has 12,700 miles, bought new in late NOV 2011) had the infamous CEL appear ~2wks ago... First visit to a Jeep dealer they flashed the system and cleared the codes and sent me on my way saying it was a random misfire on Cyl 2. And it should all be fixed. Thought OK. Good. Two days later the CEL comes on again! Call same dealer and they said it would be a week before they could get me in... so I called another dealer and they got me right in. New dealer did more thorough investigation and found that I have low compression (cyl 2) and they will need to replace the heads! Can't say I'm happy ..but I can say that Jeep has taken the bull by the horns and is getting it fixed and paying for a rental as the heads are on back order! Apparently there is a back order of over 400. Hope I get moved up the list or the supplier pumps out some parts. Will keep everyone posted.
I will say that if this had happened one mile after my warranty had expired that this post would be less pleasant.:eek:
 
#31 ·
My friend with a 2012 Arctic called me about the same exact thing today. They told him he has a misfire on cylinder 6. He brought the truck in for service as it hit 10K I believe. They said one of the valves was bent, and the cylinder head needs to be replaced, which is on national backorder. Friend isn't happy. I'm going to take mine in for service in a few days as well, and hope I don't have this problem.
 
#32 ·
I keep seeing bent valves, and valves kissing the piston top in threads about this problem. Anyone mention anything about the piston that bent the valve? Any dings or damage to the piston as well? Pistons and valves are not supposed to collide, touch, kiss, etc., damage can also occur to the piston as well. Just wondering that's all.
 
#36 ·
My 2012 Wrangler has been diagnosed with the bad cylinder head, cylinder 2 is dead syndrome. It does not run like cylinder 2 is dead/not firing. In fact everything seems fine with no detectable misfire. I just wanted to find out why the check engine light comes on intermittently. On a high note, I was told 1.5 to 2 days for the repair.

13,000 miles
 
#37 ·
Add me to the list...2012 JKU w/ 20,000 miles CEL diagnosed today as cylinder #6 misfire. At dealership now waiting...
 
#38 ·
My check engine light came on last week and it was the number four cylinder. They called today and said that the parts are here and that I should be up and running again by Wednesday. I was told that the number four cylinder was firing 40% lower then what it was suppose. They have been covering all of my rental expenses and my Jeep is 2012 and bought in November of 2011.
 
#39 ·
My 2012 wrangler had the same problem. Took it in and they said it was a bad coil. Fixed the coil and but didn't fix the problem. Then they said it was a couple of bad valves. Replaced the valves, didn't fix the problem. Has been a week without my Jeep. Called today and they said bad cylinder head, will take another 2-3 weeks to get the part in because of massive backorder. WTF mate?!?!? called Chrysler Canada to tell them about the issue. They told me that they haven't had any logs/recall issues about this. Issued me a case # and are trying to speed up the part order. stuck with a tiny patriot.
 
#40 ·
Cyl 6 Misfire

Just got a call from Jeep, Add me to the list as well. CEL is Cyl 6 misfire. Parts are backordered nationaly, probably wont see parts for 3 weeks, but they told me I could still drive it safely. If it's bending the valves, youd think they would have told me not to drive it.
 
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