2012 Wrangler cylinder head failure

The check engine light came on again on my Wrangler (29K miles) over the weekend with a P0300 fault (multiple cylinder misfire), this was the 3rd time in the past couple months. I had hooked up my laptop and cleared the fault code previously as there were no other symptoms, but on this 3rd time, it was accompanied with a rough idle, so it is time to take it to the dealer (Colorado Chrysler Jeep) for warranty coverage. This is painful to me, as this is the first time in my 25 years of 4x4 ownership that someone else will put a wrench on one of my vehicles (never had one with warranty before buying this brand new Jeep).

The LH cylinder head problem on the 2012 Pentastar V6's is well documented, and sure enough, they have found excessive leakdown on the LH cylinders, and I am now getting a new cylinder head put on. The service writer told me they have 5 Jeeps in there now with the exact same problem.

Additionally, I asked them to look at the following items:
1. A intermittent squeak/chirp from the front belt drive of the engine when hot - they told me today they think its a water pump.
2. A creaking noise from the bellhousing when engaging / releasing the clutch when hot. No word yet on the root cause.
3. The LH buttons on the steering wheel are intermittently inoperative. They have been unable to duplicate the problem.

I'll keep y'all posted on how this goes. Just FYI.
 
A

AngryRedBird

Guest
Thanks for the Update Geoff.. How are the dealer tech taking your suggestions?.. Typically they don't want to hear what the owners have to say.. However, if this is your third time taking the jeep to the dealer.. I'd slap the lemon law clause on the table.. Not to sound rude.. but it is the law..
 

Hilldweller

SE Expedition Society
...
2. A creaking noise from the bellhousing when engaging / releasing the clutch when hot. No word yet on the root cause.
....
Good luck on it.

I had my release bearing replaced in early November and it didn't stop the problem. Along with the noise, at idle it sounds like a rusty coffee can full of ball bearings swishing around and sometimes there's a false 4th gear that's annoying.
My USB port is often awol.
Sometimes the A/C turns on for no freakin reason.
The mysterious "clunk"

But I still love driving it. Just afraid to mod too much and give them a reason to deny warranty. Lifetime warranty...
 
LOL! Not the 3rd time, this is my very first time into the dealer since I bought it new. I reset the fault code myself previously since there were no other symptoms. My OE battery totally died (loose plate connection in a cell) shortly after the first time the fault light came on, so I thought maybe that was the cause. I didn't bother with warranty on the battery because I put in a much larger capacity replacement.

I'm being very careful to try to be patient and not step on their toes by telling them how to do their job! In all honesty, I've had a pretty good customer service experience with them so far.
 
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A friend of mine is a Chrysler Tech - they expect a 100% failure rate on the bad batch of heads.
Well, that actually makes me feel better about them working on my Jeep (I spent the first 15 years of my career as a mechanic), as the technician should be very familiar with the process, and hopefully less chance of a mistake.

It is good to see that Jeep has acknowledged the error and is covering new head replacement under extended warranty if necessary.
 

Yarjammer

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

I'll keep y'all posted on how this goes. Just FYI.
I have this problem as well. I've just sorta lived with this issue since I'd rather be driving it than making payments on a rig sitting at the dealership while they pretend to troubleshoot it (been there, done that but didn't get the t-shirt). If it goes in for something major, then I will have them take a look at it. Definitely keep us posted on how it turns out.
 

kojackJKU

Autism Family Travellers!
Hate to say it but its the pentajesus biting people in the ***. My good ole "minivan" motor still trucking no issues. I guess the new minivan motor is no better. What happened to the recall on the new heads? You should just be able to get it all fixed up free of charge.
 
No question the 3.6L Pentastar is a minivan motor too! And the new head replacement is absolutely covered under warranty for no charge.

After test driving several 2010 and 2011 3.8's, we decided on the 2012 because of the substantial extra power, torque, and smoothness of the Pentastar. IMHO, it is a night and day difference in the 2011 vs 2012+. The new and used 3.8's that I drove were gutless, noisy, and vibrated at higher rpm (3500+ rpm) under load.

I had hoped that Chrysler had all the bugs worked out on the new engine since it had already been in production for a couple of years in other models besides the Wrangler. Unfortunately, I was wrong, and I should have waited another year! Time will tell how the Pentastar holds up in the long run.
 

kojackJKU

Autism Family Travellers!
I had a 2014 sahara rented for a week in montreal, the power is not a massive difference as far as I am concerned. The way everyone was talking around the forums you would think you would have to watch spinning tires from starts etc. Mine is not gutless, vibrate or whatever. its works fine. no, its not as powerful. but the difference in power is not a huge change.
 
I didnt mean to come across like I was bashing your Jeep, and I apologize if I did! Maybe I just drove some duds. Your 3.8 JK runs and my Pentastar JK is in the dealer getting a cylinder head put on. 'Nuff said! :)
 

verygneiss

New member
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
 

kojackJKU

Autism Family Travellers!
I didnt mean to come across like I was bashing your Jeep, and I apologize if I did! Maybe I just drove some duds. Your 3.8 JK runs and my Pentastar JK is in the dealer getting a cylinder head put on. 'Nuff said! :)
Nah, I always have a little bit of fun with the guys who come on the forums and say OMG the pentastar is mind blowing power. Its not. No hard feelings bro.
 
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