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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?
 
#104 ·
Hey all I found this article on the jeep wrangler cylinder misfire...
Chrysler to fix defect in 1,000 V-6 engines
Yeah. I saw something similar a while back. You know this article was posted in Aug 2012 right?

The article I saw went further to describe some kind of manufacturing quality issues that caused the problem with cylinder misfiring. I wish I could find it again.

Suffice it to say, I'm glad I have not had this problem. I've had VERY few issues with my 2012 JKUR
 
#105 ·
Well here I am, right on cue. I'm right around 20,000 miles and my CEL is on. Code reader says cylinder 6 misfire. I've got an appt to take it in to the dealer tomorrow to have it looked at. I'm glad I read this thread because I think I'm now a lot less likely to accept a line of BS from them. What's really bad is I had a long road trip planned for next week and I don't think I'm lucky enough that they'll have the parts in stock and be able to get it fixed in time. And I hate to think what kind of loaner I'm going to get. The timing couldn't be any worse.
 
#106 ·
Here's an update. Took it into the dealer today and told them I was pretty sure of the problem and I just need them to confirm it is the cylinder head. He says they'll try replacing the coil and some other minor stuff first and see if that fixes the problem. I asked him how many new Pentastars has he done that to and had the problem go away. He said NONE. I said then let's not waste our time on that and get down to brass tacks. I told him I want to know if my cylinder head is bad right now. He seemed resigned and didn't give me an argument but said it would take six hours as opposed to the two hours they estimated yesterday just to diagnose. I asked him how long after that to replace the head and he said he would have to order the part and have it shipped. I then blew up. I told him there was no excuse for not having those in stock because this has been a known issue for quite some time. He told me that Chrysler has made this a "restricted item" and dealers can now only get so many a month. Bottom line is I'm going to have to use their loaner, a Jeep Patriot for my trip but I should have all the work done when I get back.
To tell you the truth I'm glad this issue cropped up now so I can get it behind me. I don't care what they say, ALL of these engines (pre- head redesign) are vulnerable to have this happen at some point in their life. I'll post updates as they occur.
 
#108 ·
Happened to me today 7/12/13! My check engine light on my 2012 Rubicon came on today at 10,064 miles. Can't get into the dealer until Monday to have it checked out. Also, not sure if this has happened to anyone else but right after I bought the Jeep new last August I had a issue with a transmission leak out if the lines because they were overlapping I believe the power steering lines. Can't wait to see what the dealer tells me about the light. Will keep you posted.
 
#109 ·
Check Engine Light - Cylinder 6 Misfire

Same thing happened to mine...2012 Wrangler Unlimited Altitude. They are going to have to open up your engine and replace the cylinder head. Don't let them tell you anything different. They did this to mine and its been running fine since then. The work is under warranty as it is a recall.
 
#111 ·
Well, I just got a call from my dealer that my Jeep is done but I'm still on vacation with their brand new Dodge Durango. I have to admit this is a pretty sweet ride and has probably been a much better highway vehicle than my Jeep would have been. Also there will be about 2500 miles less wear on my own vehicle so maybe there is a silver lining to this. One thing I want to ask you all is if there is anything I need to ask them or look for when I pick it up to ensure the job was done right, or do I just drive it away and monitor it for leaks and other oddities? Thanks.
 
#115 ·
#112 ·
Cylinder #6 misfire

Just got my 2012 Jeep Wrangler Sport back from the dealer. New vehicle with 28,000. miles and had to replace cylinder head. My second jeep, but first Wrangler and I love it. I have always got 19 MPG out of my Jeep Wrangler, today on a short trip I'm only getting 11.8 MPG. What could be wrong with it now. I will contact the dealer Monday. Has anyone had this problem or any ideas? Thanks
 
#113 ·
Just got my 2012 Jeep Wrangler Sport back from the dealer. New vehicle with 28,000. miles and had to replace cylinder head. My second jeep, but first Wrangler and I love it. I have always got 19 MPG out of my Jeep Wrangler, today on a short trip I'm only getting 11.8 MPG. What could be wrong with it now. I will contact the dealer Monday. Has anyone had this problem or any ideas? Thanks
Of course it all depends on how it was driven during that short trip vs when you were getting 19. . Maybe drive it a little more to get a good average. I just got mine back from the dealer yesterday. So far the mileage seems to be about the same. It's too soon to tell for sure though. I am still apprehensive that they forgot to tighten something down, reconnect something, or some other little thing that will crop up later. BUT....I'm still glad to get this behind me....maybe......hopefully.
 
#117 ·
15,500 miles on my 2012 JK, and got a Cylinder #2 misfire. Dealer was well aware of the cylinder head issue, but said they have had some success with a re-flash of the PCM. 10 miles later - CEL lights up with cylinder #2 misfire. Called the dealer. Bringing it back to get the head replaced.

FWIW - my Build Date is 10/2011.
 
#118 ·
Got a cylinder 6 misfire. I'm planning on travelling 1500 miles round-trip this weekend, will this be a problem? I haven't noticed anything different with how it drives. I've gone on a couple of 200 mile trips the last couple of weeks since it came on and haven't noticed anything. The dealer wouldn't recommend driving on it, but he wouldn't say I can't drive on it either.

(I just hit 20,000 miles fyi, 2012 Unlimited Sahara, got it in May 2012)

What do you guys think?
 
#119 ·
I'm at 34k and have not had a problem. I ordered my Jeep in Sept '11 and took delivery in Nov '11. I was built in Oct/Nov. at some point there was a delay. For several weeks. I wonder now if that was when they discovered and fixed the issue.

I read the page on finding your build date, but was unclear because it went back and forth. Has anyone successfully identified the date?
 
#120 ·
Friends, I called Chrysler Customer Service number today and had a nice conversation with the rep about this problem. I obviously have concerns about this problem and i needed warranty details. So some of you may know and others wont BUT from what she explained to me, the Cylinder head is part of the 100,000/5 year powertrain warranty that comes with all our Jeeps. Most of us, God willing will be driving and enjoying our JKs well beyond 100,000 miles (Hopefully) so if this cylinder needs to misfire, it needs to happen now so it can be fixed....OR they may recall them all just to replace the HEAD with a more "Robust" one. I have 24,000 miles on mine, Purchased in October 2011, and she runs strong and no ticking noises or anything like that....My only concern is that it seems like it will eventually catch up with every single engine...trying to still figure out why some are effected and others not "Yet"......By the way, off topic, but the Customer Service rep did mention there is a recall notice going out next week about the Transmission Cooler line......no idea what that is but i guess i will be bringing in her in soon..........:hide:
 
#121 ·
Just crossed 30k miles this weekend. Mine was a day one build as I watched it on the online tracker the day they started building the 12's. No unusual ticking, lack of power or dropped mpg yet. I kind of wish that if it were going to be a problem, that it would go ahead so I could get it over with.

Oh, I beat the snot out of it every day. I am not easy on it by any means.
 
#122 ·
I wondered about the 100k/5yr warranty. That makes sense. Glad to hear it... Thanks for sharing.

Regarding the "ticking" folks are referring to, mine makes more of a clacking clacking noise and I've isolated it (as best I can) to the drive train because it goes always shortly after I depress the clutch and some spinning part slows to a halt. When I let the clutch out, it starts up again.

I assume this is not the ticking related to the engine people are referring to? Right?

Any thoughts on what that might be? Should I take it in and have them look at it? It's been doing it for a long time! Since before 10k miles. Maybe even sooner. Never seemed to cause any issues and I only hear it at very low speeds or when stopped so it's not a nuisance.
 
#124 ·
observations a year later

You know, mine never ran rough, never lost power, never made a ticking noise, never got worse fuel mileage... it was just that the check engine light would not go off. Not being able to use the remote start was the most inconvenient thing about it, up until I had to leave it at the dealership for a week, while they changed the head.
BTW, if you've had that done, check all the wiring harnesses that are supposed to be routed across the the topside... 20K miles AFTER my head replacement, check engine light came on, along with the traction control light... this time I did lose power, and the tranny wouldn't shift automatically (it would bump shift, but the computer had quit controlling shift-point) anyway, I limped into the dealer (different one) and they quickly diagnosed it; the dealer who had replaced the heads had failed to properly secure the wiring harness, and it had worked its way to the point it was in a minor bind, which, over the course of 20K miles, eventually caused it to break a couple of pins in the connector.
My biggest gripe in all this is that Jeep/Chrysler service writers and counter-jockeys are STILL pretending like they don't know there's a problem with those engines. The fact that there are still message boards all over the internets with people going "my CEL came, dealer says its a misfire cyl 2... what up with that; anybody else heard about that?"
Some dealership's service managers are more honest than others, and it's very clear they've been told to play ignorant. I understand they had a big problem, what with fixing the tooling that caused the defect, and then manufacturing enough heads to catch up with the ones already sold, and not slow down production of new ones... but who says you don't slow down production of ones to sell until you're damned sure you fixed all the ones you already sold? That's what a company that wanted to ensure the loyalty of its customers would do. I love my jeep, but I really hate the way Chrysler has dealt with this. I'm in the market for a hiway car (but not a car), and would love to have a Grand Cherokee Overland with a Hemi. But first I have to decide whether to give this company any more of my trade.
 
#126 ·
Amazing that the dealers also pretend that a software "reflash" will fix a mechanical misfire when you walk in, most likely knowing full well that you'll be back shortly.

God I hate those shady lying stealerships...they not only steal your money but your time and sanity.

Funny how I never had any issues with Infiniti, Acura, or Lexus dealerships, though. The service makes you want to go there...though you probably won't ever have to.
 
#128 ·
Hey I'm having the same problem with mine. The dealership I went to was truthful about it but also has a waiting period of three weeks and the part is also on back order. Do you guys know what's the worst that can happen with me driving my jeep. Also my jeep has almost 18,000 miles, do you guys know if its still covered under warranty? Thanks
 
#130 ·
Definitely under warranty. When I had mine done, the "report" found one of the exhaust valves was sticking, and was burned and pitted. I would guess that continued driving would further damage the valve resulting in more misfires, rough idling, and lower milage, but otherwise safe to drive.

I had noticed some rough idling a few weeks prior to the CEL light coming on - so the valve was possibly sticking then, but not causing enough misfires to trigger the CEL.

As for the backorder - I had mine done last week, and it only took a few days for them to get the head (I'm in So. Westchester - not too far from No. Jersey). Perhaps try another dealer?
 
#131 ·
Yeah I talked to the dealer today and thy said its covered under the 3 years 36,000 mile warranty. And I scheduled an appointment at a different deal that had it in stock. For Thursday, I haven't noticed any drop in mpg or rough idling the only rough idling I've noticed is when the car is warming up.
 
#134 ·
So i may be in the same Boat my jeep been back and forth for the last few weeks. and months $ months ago traction control light went on and stayed on. and weird noise coming from engine. Turns out bad sensor and water pump. finally parts came in last week when i got a check engine light. they replaced the water pump i left everything was good. 2 days and engine light came back on for few hrs. i called them came in and my sensor was ready they switched that out top me engine light is all clear. on the way home light came back on. calling again to bring it back also going to check the code myself tomorrow. my truck has 17,000 miles on it 2012 Unlimited sport.
 
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