P0306 STRIKES RUBICAT AGAIN : Jeep JK Wrangler Cylinder 6 Misfire

Last week, Cindy and I packed up Rubicat and headed out bright and early to make our way down to Shaver Lake and with plans of taking her out to the Dusy Ershim Trail. Unfortunately, just as we were passing a pickup pulling a trailer up a long grade about a half hour out of town, our engine started to run really rough and the check engine light on the dash started blinking and dinging at us. After pulling over to the side of the highway, I popped open the hood and did a quick visual check to see if anything obvious could be seen.

With everything looking good, I decided to hook up a Superchips Flashcal we had with us to see what check engine codes we were getting and… we were getting a dreaded P0306. Translation, a Cylinder 6 Misfire.

Now, for anyone who has a 2012 Jeep JK Wrangler or even in some cases, a 2013, you most likely know that the all new 3.6L Pentastar V6 engine that had just come out was prone to having a bad cylinder head. Like so many of you, we ended up having to have ours replaced very early on and thankfully, under warranty. The link below chronicles what had happened to us back in 2012:
2012 Jeep JK Wrangler Check Engine Light on RubiCAT – P0306

When Rubicats engine started to crap out on us this time around, we knew we had experienced something like it before but were hard pressed to think it might be the same thing. But, after seeing what code we were getting, a P0306, it was hard not to think we might have another bad head. Sure enough, as we hobbled our way back home, Cindy started to do some research and much to her surprise, found there was in fact a new TSB that FCA issued and it was for an extended warranty on the “left cylinder head on 2011-2012 and some 2013 vehicles equipped with the 3.6L engine”. The TSB 09-002-14 or X56 – Extended Warranty now covered the cylinder head “10 years or 150,000 miles (whichever occurs first) from the vehicle’s In-Service Date”. Needless to say, as soon as we got back home from our trip, we made an appointment at Carson City Jeep and brought her in today.

Just to make sure we didn’t influence anything, we kept quiet and let our service advisor, Tom Koche do a scan and come to his own conclusion as to what might be wrong. And, while he couldn’t give a definitive diagnosis, he pointed out that we had a cylinder 6 misfire and explained that it might be a bad cylinder head. He went on to inform us that if it is, FCA had extended the warranty on it and that it might get covered. Too soon to say for sure what the exact problem is but I was happy to hear him volunteer this information rather than have me bring it up.

We won’t hold our breath but if we can get this covered under warranty, we will be two very happy campers. I’ll be sure to post up more once I find out what’s going on.

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P0306 STRIKES RUBICAT AGAIN : Jeep JK Wrangler Cylinder 6 Misfire