Hi all,

I have a 2012 JKUR (3.6L) that blew its 2nd oil cooler on me a couple of weeks ago. I drove it home, it got hot...but never got above the 3/4 temp mark so I limped. It into the garage. I opened the hood and steam was billowing out around the intakes.

This wasn't my first experience with this issue...I even had a spare Oil Cooler on hand expecting this to happen again. So I jumped in, replaced the Oil Cooler and put everything back together. When I went to start the Jeep the first time, it fired right up but was running terribly. Figuring I missed a connection or something, I dove back in...but nothing was out of place. On the second attempt to start it, the Jeep just cranks...it cranks for a long time and it will even turn over but then immediately dies.

I'm out of ideas, I've replaced the crankshaft sensor, I replaced the lower intake with all 6 injectors (needed to be done, old unit was cracked and I got a good deal on the replacement with injectors). I tried the fuel relay bypass in the TIPM, replaced all of the coils, battery has 12.3 volts, all electrical connectors are tight, no security light...and the worst part, it isn't throwing any codes at all!!! Any help is much appreciated.

 

Stop throwing parts at it. First thing in modern vehicles is to do a scan for DTC trouble codes. Then go from there. Let us know what they are then we can narrow it down a bit.

 

As stated, I don't have any DTC codes present or stored. Whether I use my scanner or turn the key 3 times nothing shows up.

 

How old is the battery? 12.3 is a little low for these Jeeps, and a low battery will cause the JK to do a bunch of strange things.

 

Red Top Optima, I put it in about 5 months ago. It was probably 12.3 after cranking it a bit...but I checked and the terminals are tight.

As I wrote the above, I actually got it running...but for some reason, I had to hold down the throttle when cranking and as it was starting. Then it finally stayed running. Drove around the neighborhood and it's running fine again. Still no codes...so weird.

One more addition if anyone comes across this post, I also did a Throttle Position Relearn procedure in JScan and that helped the starting tremendously. Runs and drives normally again.