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JKU engine advise

Leakysami

Member
Joined
Jan 28, 2020
Messages
9
Location
South Carolina
I bought a 2012 JKU Rubicon used about 2 years ago. great condition, shitty lift, 35x13.50r15's. Toyo MT's. After owning it a little more than a year. I decided it was time to get rid of the horrible Procomp shocks. instead of just replacing the shocks I jumped off the deep end and ordered the EVO Mfg King coilover kit with all new links . The same day I received the first tracking number, Cylinder 6 dropped a valve. Thankfully Mopar knew that this was a problem and had extended the warranty on the left side head to 150,000 miles. So after a couple weeks and lots of phone calls I was able to have it replaced under warranty. We then got the new lift installed along with some 37"s and 5.13 gears. All was good until last week. BOOM, Cylinder 5 does the same thing. Now the Jeep is just sitting there in the garage.

I do not know the best way of going about getting it running again. Do I fix the 3.6 and hope for the best? Find a used one? Save up and LS swap it?

Has anyone on here gone threw the same thing? if so what did you do?

Thanks
 
Did you have any other problems before number 6 went? I've got a 2012 rubicon with 95k on it and it uses a quart or 2 or 4 between oil changes.
 
I dont have any specific experience with the 3.6 so I am speaking just from general mechanical experience. A quick search on the issue shows that the problem your having seems to be fixable with good results. It only seems to be an issue with 2011 to 2013 models. Chrysler fixed it after that. That being said it really comes down to cost. The cost of repairing the head on your motor is going to be a lot less than purchasing a new to you LS (that could have issues), adapter to your tranny or a new tranny, new drive shafts, motor mounts/tranny mounts, exhaust, fuel lines,maybe fuel pump, wire harness adapter,ECU + flash. That is just a general picture of what is involved in the swap. Is the swap worth it? It is not, on a straight monetary comparison. However if you want an excuse to upgrade to a V8, then the head issue is a perfect excuse.
 
Now the Jeep is just sitting there in the garage.

I do not know the best way of going about getting it running again.

Sounds lke a good start to the swap. Just like everyone else's progress on an LS swap? haha
 
Before #5 failed I was adding anywhere from 2-6 quarts of oil a week. depending on how hard I was driving. No smoke, no leaks.... no idea where it was all going.
I do not have any kind of warranty left with Mopar. They only extended the warranty on the left cylinder head because it was such a wide spread problem. The dealership said that there was a list of 2,400 people waiting on the same part. (who knows if that was true or them buying time)
"Dropped a valve" is the term the tech used. If I remember correctly it was seal? that was leaking? checking the paperwork, the left cylinder head failed the compression test.
Once we get a break I will do a compression test on the right side, then inspect internals.
I know it will be rather expensive to do the LS swap. but at least then I shouldn't have to worry about the drive train anymore. well except for the axles. Anyone know where an LS swapped jk is getting parted out?
 
My 2012 Rubicon just went down with 97k on the ticker. Took it to a mechanic and he says the head is cracked. Was adding 8-10 quarts of oil between oil changes and it starting missing and running bad that I could hardly drive it. Was looking into putting a motor out of a wreck in it and was wondering if anybody knew if the 14 and newer year model motors would work. Thanks in advance
 
Finally got a chance to dig into the jeep using the real scanner and not my Flashcal. That scanner is showing misfire cylinder 6. again..
Talked to the service manager at the dealership. they said to bring it in, if it is cylinder 6 they will warranty a new head.
I am curious why the scanners are reading different.
scan1.jpegscan2.jpegscan3.jpeg
 

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