2012 JKU 96k miles major oil leak.


Looking for anyone who has had the following symptoms and or problem:

2012 JKU 3.6L

Right side head (sitting at the steering wheel) area appears not to be leaking but pouring oil. So some jack wagon almost hit me, in avoidance of a near collision I went from a gradual drive off to full throttle. Once I cleared his path which was straight at my Jeep I let off the throttle immediately followed by the smell of burning oil white smoke in thru the air vents. Heater was running. I shifted the Jeep into neutral shut off the engine and got off the road, popped the hood checked everything out right away was low on oil. Got under the Jeep and noticed the entire transmission bell housing was coated in oil some was still burning off the exhaust.

So I got the Jeep home cleaned it all up, did a full oil chance was about that time anyway. Let it idle no leaks, took it for a drive did one hard acceleration as if merging into traffic to try to replicate the situation, stopped and checked and new fresh oil had leaked all on the transmission again. Went and bought a bore scope checked all under the intake, back of the engine everywhere I could access. I was thinking or well hoping that is was as simple as the oil sending unit that is a pretty easy job. Regardless changing the sending unit requires pulling the intake manifold, so I guess I am going to do that this Thursday and get a better look. After inspection it looks like it could be the head gasket, the entire valley under the lower intake plenum is coated with fresh oil. The oil sending unit is under the upper plenum and that area appears to be dry. The Jeep is running perfect, no light, no codes, no loss of power. Oil leak is only noticeable under load and at higher RPM(rare for me) also (higher as in like dropping into passing gear) which of course is when the oil pressure is on the higher side. Coolant is fine, no fluid mixture on either end. No bubbles in the coolant indicating exhaust and coolant mix, no smoke nothing just oil running down the block.

Anyone have a related issue?

James Blue


I did not know that, appreciate the response I am going to look into it. Will check back I hope it is this simple.

Again thanks never knew there was an oil cooler here. From his description oil in the valley and bell housing sounds like my issue.


Well simple as in well with in my capabilities. I was trying to get prepared for worst case of pulling a head. Got all the torque specs for everything made sure the new oil cooler is the newer style ordered it today out of North Carolina dealership got is $191.50 2 day shipping really expected it to be a lot more. Should be here Thursday taking a the day off and plan to knock it out. Will toss up some details as I get into it.

Again thanks for the info, would have never looked here for an oil cooler... Thanks Fiat....
It is your Oil Filter Housing/Heat Exchanger. It will crack along the base and you can't see it from the top of the motor under the lower intake manifold. Your evasive maneuvers either shifted the oil that has been pooling on your motor, of finally cracked the think even more. Just had mine replaced at 90k miles on my 2012 JKUS. It was leaking radiator fluid down my bell housing like a sieve, however, it can be oil or coolant depending on where the crack is located on the heat exchanger. Mine was about $700 to fix at the dealer, but they warranty the new part for two years, so some piece of mind.

It is a faulty, shitty part by Mopar and ALL WILL FAIL at some point. Even the JL have the same part (different part number as I understand, but same part) and those will eventually fail also...
Well there is a new design that was done to address this issue. But maybe they did not creat another one in the change process... Prat was pretty reasonable priced, worked on it for about 30 minutes this morning got all wiring and hoses off gonna pull the intake on my lunch break. Part should be here today hope to have it back going by lunch tomorrow but I have all weekend so going to change radiator hoses, thermostat full coolant flush, and spark plugs. Jeep is actually at 89,000ish miles I don’t know why is though 96k.
Total tare down time from un hooking the battery to removing the cooler was about 1 hour. Got to clean the valley out, clean up the manifolds and valve covers and the new cooler should be here today. Grab a set of gaskets from Napa and toss it back together.

Pictures re-uploaded.


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Well reassembly took about 3 hours stop and go. Just took my time double checked everything. Initial on start up it blew the fuel line off the fuel rail. Reattached that and all went well. Drained the oil, filled itnwith new stuff. Let it idle up to normal temp. Shut it down drained the oil again and changed filter. Filled back up and it is all good. Thanks for the input on what to look for.

Only real pain was changing spark plugs in the right head, dual battery system interfeared.




Sucks to dump new oil but just a little insurance. In the process of changing the cooler coolant did get in the oil.
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