2012 Wrangler cylinder head failure

[AngryRedBird]

kojackJKU I'm somewhat pleased with the results we've been getting with the 3.8L V6.. as compared to the inline 6.. which had so many problems.. and I think it's time to baby the engine a bit more.. new Hoses and Belts on order..

 

[kojackJKU]

As I said, I have 157k on my rig 2011. It has never been in the shop for anything motor related. Do I wish I had a hemi? yep. Do I need it where I need to trade in my jeep and take on another payment, considering mines paid off....NOPE

 

[codesertrat]

Geoff,

I just got my '12 Rubicon out of the shop today and had many of the same problems that you're experiencing. I've clocked 32k miles so far, but my check engine light had been on since around 30k. I put off taking it into the shop and just erased the codes a couple times with AEV's Procal. I hadn't noticed any adverse idling or engine problems, and never had it in the shop for more than an oil change. Last week after the codes kept returning I went ahead and took it in. I was pulling p0302 cylinder 2 misfire (probably among others). It failed a compression test, and they replaced the left cylinder head. The next day (thankfully still in the shop) it threw an engine light again (P000D & P0018), something with the camshaft and crankshaft. Turns out the exhaust cam phaser was inoperable, so they replaced both the intake and exhaust cam phaser (no clue what all that is to be honest, just reading the sheet).

Also went ahead and got the power mirror & transmission cooler tube recalls taken care of. I've heard that people who had the cylinder head problems a year or two ago had a hard time convincing Jeep or the dealers that it was a warranty issue. Luckily this issue is well known now and I had no problems getting in and out and all fixed up. My Jeep does run better now and feels a bit more nimble.

Lastly, It's good to hear someone else hears a chirping/squeak from the front of the engine while hot. I thought I might be hearing things. I usually only notice it after I make the drive into my office, then start accelerating/turning up the echoing parking garage. Sounds like a whistling noise (two toned usually). Alas, they said they checked for it but couldn't find it or replicate it. Let me know if it turns out to be the water pump for you.

Just wanted to share my recent experience.

Good Luck!

Steve

Steve,

The cam "phasers" are the variable valve timing mechanism. They probably installed something incorrectly with the head installation. I'll let you know on the water pump - hopefully it fixes the noise, as it is very annoying.

 

[MTSN]

Steve,

The cam "phasers" are the variable valve timing mechanism. They probably installed something incorrectly with the head installation. I'll let you know on the water pump - hopefully it fixes the noise, as it is very annoying.

Hi Geoff,

I just bought a certified 2012 JKUR a month ago, and twice when I've started it there was a really rough idle and CEL. I turned it off, restarted, and the issue "went away" both times. Several times when I've been parking in the garage however I've smelled something that sort of reminds me of a coolant leak sort of a smell, and I'm wondering if you ever noticed that symptom? I'm still covered under warrant thankfully, and I wouldn't be surprised if it's the same issue you've experienced. The Jeep overall was in as new condition when I bought it, and I've really enjoyed the power though the mpgs have been disappointing. My first tank was 13 mpg and my second tank was 11.8 mpg :Wow1: I have a feeling I'm to blame for that mostly because I have a city commute, and I've been enjoying the quickness coming from my Land Cruiser! I would not be surprised though if I'm experiencing the cylinder head issue if it could be hurting the mpgs as well.

 

[AeroSynch]

I went through the same issue about a month back with my 2012 6 Speed. It happened with 29K and I ended up going to the dealer a total of 4 times. They ended up replacing the head, then a camshaft position sensor, then another sensor, and finally the camshaft phasers, lifters, etc on the LH side since they were worn according to the dealer. Seems to be fixed currently as no light has returned.

Good luck!

 

[calicamper]

Wow just found out about this from a neighbor his jeep is currently getting worked over for the same issue roughly the same mileage point also. He was pretty miffed about it. Sounds like he'll probably dump the jeep after he gets it back his prior trucks were all Toyotas so fair guess he's going back to Toyota. Too bad because Jeep really seemed to have hit a home run with the new designs. Hopefully the fix is proper vs a patch job to hide a bad design. My 91 3L Toyota was a bad design ;-) blew two heads in two years.. That was not fun.

 

[GetOutThere]

3. The LH buttons on the steering wheel are intermittently inoperative. They have been unable to duplicate the problem.

Pretty sure this is a JK thing. Mine has the exact same issue. Annoying as hell. I haven't mentioned it to them yet, because I knew I'd get the same answer you did. "Cannot replicate". Code for "turned it on, pressed button, button worked."

Wouldn't even take 5 minutes to replicate it. I'd say mine is a 70/30 split on working to not working.

 

[kojackJKU]

I have the issue, but if you just honk the horn, and they all work right again. I think its something in the programming.

 

[codesertrat]

I have the issue, but if you just honk the horn, and they all work right again. I think its something in the programming.

You're serious about that? If they don't fix it, I'll have to give that a try.

All of the 'buttons' in the JK's aren't really 'buttons' in the normal sense. The horn, turn signal stalk, headlight switch, wiper switch, and steering wheel buttons are all electronic signal generators that create a LIN bus (single wire communication network) message to some type of a dash or steering column control module; the steering column control module then sends a CAN bus (two wire communication network) message to the TIPM (Totally Integrated Power Module) under the hood (TIPM is the fuse / relay box on the right side), which then receives the network message and activates the appropriate relay or circuit.

This is why I am trying to find information on the communication network architecture used in these Jeeps. When things don't operate, its usually some type of simple communication failure - the pulsing multiplex square wave message didn't send, was garbled, or wasn't received because of a resistive connection, interference, or other simple wiring problem. The advantage of using communication networks in modern vehicles is the simplification of wiring and connections (Two communication wires take the place of a whole harness) and ease of service (if you have the right tooling). The downside is the reliance on computer software programming for all functionality and a lack of serviceability (if you don't have specialized tooling which can 'talk' on the network to the other controllers). That specialized tooling is Jeep dealer only right now as far as I can tell.

 

[codesertrat]

I'm supposed to get my Jeep back on Friday. I'm keeping my fingers crossed. The service writer told me that this is a casting defect with the LH cylinder head, which is why the RH side doesn't seem to be affected (RH and LH are totally different castings). He said they have 2012 3.6L's almost constantly coming in with this problem. It seems to be an almost 100% failure as others mentioned. At least Chrysler is standing behind them - certainly a very, very expensive quality screwup on someone's part in the manufacturing process.

 

[brianjwilson]

Boy I wonder why so many of us here sold our 2012+ JKs and bought Toyotas?

Sorry to hear of your trouble. My 2012 was my first and last jeep/Chrysler/dodge vehicle. Warranty fixes on the transmission and transfer case right off the bat, tons of money fixing stupid weak engineering designs, and knowing that the cylinder head and water pump were going to cause problems soon. I'm working out of state at least 60% of the time, and like to travel when I'm off, not constantly fix a jeep and make dealership appointments.

I was also unimpressed with the 3.6. It was just ok but nothing more. I bought a 2015 tacoma with the 4.0l before they switch to a car engine in 2016 as well.

 

[Yuccahead]

I took delivery of my 2013 in September and had my water pump show the same symptoms by around November. Took it in to the dealership and they replaced it but not before the new tech got all worked up by the new color of the antifreeze. If I recall correctly, it was originally purple.

 

[kojackJKU]

You're serious about that? If they don't fix it, I'll have to give that a try.

All of the 'buttons' in the JK's aren't really 'buttons' in the normal sense. The horn, turn signal stalk, headlight switch, wiper switch, and steering wheel buttons are all electronic signal generators that create a LIN bus (single wire communication network) message to some type of a dash or steering column control module; the steering column control module then sends a CAN bus (two wire communication network) message to the TIPM (Totally Integrated Power Module) under the hood (TIPM is the fuse / relay box on the right side), which then receives the network message and activates the appropriate relay or circuit.

This is why I am trying to find information on the communication network architecture used in these Jeeps. When things don't operate, its usually some type of simple communication failure - the pulsing multiplex square wave message didn't send, was garbled, or wasn't received because of a resistive connection, interference, or other simple wiring problem. The advantage of using communication networks in modern vehicles is the simplification of wiring and connections (Two communication wires take the place of a whole harness) and ease of service (if you have the right tooling). The downside is the reliance on computer software programming for all functionality and a lack of serviceability (if you don't have specialized tooling which can 'talk' on the network to the other controllers). That specialized tooling is Jeep dealer only right now as far as I can tell.

I am 100% serious. It may take 1 or 2. but you will notice it right away that they function great for a month or more then act up a bit, HONK, and your good for another while.

 

[kojackJKU]

Boy I wonder why so many of us here sold our 2012+ JKs and bought Toyotas?

Sorry to hear of your trouble. My 2012 was my first and last jeep/Chrysler/dodge vehicle. Warranty fixes on the transmission and transfer case right off the bat, tons of money fixing stupid weak engineering designs, and knowing that the cylinder head and water pump were going to cause problems soon. I'm working out of state at least 60% of the time, and like to travel when I'm off, not constantly fix a jeep and make dealership appointments.

I was also unimpressed with the 3.6. It was just ok but nothing more. I bought a 2015 tacoma with the 4.0l before they switch to a car engine in 2016 as well.

Good luck when your Tacoma is swiss cheese in a couple of years and useless.

 

[codesertrat]

Toyota does not offer a vehicle that compares with the capability and features of a Wrangler - a Tacoma is not a suitable alternative in my opinion and 4runners are ugly and outrageously expensive. FJ Cruisers are no longer in production, and were also horribly ugly and expensive. In fact, government regulations have killed every other legitimate 4wd backcountry SUV other than the Wrangler. This cylinder head problem does not appear to be a design issue, but a manufacturing process defect.

FWIW, a friend of mine bought a brand new Toyota Tundra in '08. He had many, many warranty claims for transmission shifting problems, transfer case wouldn't shift into 4wd, and other weird electronic issues. I bought a '93 Toyota pickup in '96 with 30K miles and had clutch problems, exhaust leaks, and oil leaks. I'm not convinced about Toyota quality myself.

I'm NOT bashing Toyota, no doubt they are good quality and engineering, but I just don't see the magic compared with other manufacturers. I've constantly had a Nissan WD21/22 truck / SUV in my garage for the past 20 years - currently a mildly modded '01 Xterra with 200K miles that I've had for 10 years - and they are the most reliable vehicles I've ever owned. One of my previous trail trucks was an '87 Pathfinder with 280K miles, ran perfect, and I only sold it because I wanted an open top Jeep (I bought and rebuilt a junkyard CJ5).

The so-called 'poor engineering' of Jeep Wranglers is a myth - the 'engineering failures' mentioned in all the forums are induced by radical modifications (35+" tires) and extreme off road use. Jeep engineers are not going to design a vehicle based on 37" off road tires, lockers, and diving off of 8' rock ledges, but yet that's what the Jeep forum junkies expect. The usual Toyota Tacoma or FJ Cruiser that I see on the trail is mildly modified, only a moderate increase in tire size, and is used in a less extreme manner. Just my 2 cents.