I hate to be the new guy on the forum asking for help, but I've run these issues down on my own as far as I can. I’m posting this on a couple different forums with the hope that someone has had a similar issue.

I have a 2015 JKU 3.6 that I bought 2 years ago with around 70k. Ran good with occasional P0304 code. Previous owner had it into a shop that replaced the injector on that cylinder. Still threw the code occasionally (every 500 miles or s

o) but it would clear itself in a couple of key cycles. About 12 months ago it started throwing the code and it would only clear with a scan tool, then usually was back in a couple key cycles.

I tore into it with a plan to replace coil packs and plugs. While I had it apart, I ran a compression test; the #4 cylinder was holding nothing. I pulled the head off and one of the exhaust valves on the #4 cylinder was broken. I installed a remanufactured head I bought through Bishop Engine, tested compression on all cylinders within 10% and put in new plugs and coil packs.

It started up immediately but throwing 3 codes: P0018 Crankshaft Position Sensor Correlation Bank 2 Sensor A, P000D “B” Camshaft Slow Response Bank 2, and P0300 Random/Multiple Cylinder Misfire detected. It has consistently thrown these three codes since.

In the ensuing months I have replaced both cam sensors, the crank sensor, and all 4 Variable Valve Timing Solenoids. No change, so I took it to a shop that said it needed a new timing chain, so I replaced the chain, the guides, all 4 cam phasers, the water pump, and the thermostat. While I was at it I put in a new oil filter housing as I found out that it had been replaced previously with a version from an earlier era 3.6; I was not sure if that might affect the oil flow to the VVT phasers so I replaced it out of an abundance of caution.

Still throwing the same 3 codes.

The only thing I can think of that I have not changed is the camshafts; I put the new head on with the camshafts that came with it. Since the sensors pick up on the ring on the camshaft, my thought is the ring might be damaged or even that if it came off a different version of the 3.6 that might be set up differently. I still have the original head, so I could replace the cams with the originals as they were undamaged.

I suppose the oil pump could also be an issue if it isn’t pushing enough pressure to make the phasers work, but I have no indication that it is not functioning properly. I have not done a pressure check with a gauge.

If anyone has thoughts or can throw a lifeline to me, I would sincerely appreciate it. I am at my wits end and I’ve had this engine apart in varying degrees a half dozen times, so I feel like I am getting to the point where I am running the risk of making things worse.

Thanks,

Hubby

 

Having jacked around with my engine a few times, and recently rebuilding my timing, this hurts my head just cuz I know the amount of work involved. I don't think it's the oil pump cuz we have a common code thrown for that. If it was the oil pump i'd be highly certain you'd be getting code for it. I also don't think it's the cam phasers or oil control valves (bolts that hold em in place) cuz when those go bad you are often just getting the typical P0369 or corresponding cam sensor code as the cams aren't aligning as expected. One thought on having used the cams that came with the new head is those rings the cam sensor reads are very sensitive to magnets. I can't imagine brand new cams have been exposed to magnets along the way, but never know. It almost seems like the timing is off, but having just rebuilt mine I know it is almost impossible to mess that up with all the alignment marks. The first time time I started my jeep after the rebuilt i got slow response cam codes on both driver and passenger side. 2nd start driver's side stopped and the passenger side stayed on for another cycle or two before it went away. I presumed that was only cuz i didn't have access to doing a cam/crank relearn and it sorted itself out. No issues since. I think the code to focus on is the P0018 and that the misfire is just a side effect. I will say that when I did my job I was going to replace a cam phaser that I thought was problematic as well, and I got a bad one right out of the brand new Mopar box. It was clicking once I had the timing set and as I was turning the crank by hand.....and I KNEW that wasn't right!! I put the old one back on instead and no issues.

IDK, I know none of that was very helpful. I'm curious to see what this ends up being

 

So my daughter and I tore this down on Thursday and replaced the cams on the reman head with the ones from the original head. There was a ton of gunk built up on the intake cam sensor pickup wheel, so that may have been the issue. Also put new oil pressure/fluid temp sensors in the oil cooler housing since I have been getting an intermittent low oil pressure warning. Also replaced both cam sensors and the crank sensor with OEM parts. So far, I've got about 100 miles on it with no problems. I have a lingering bank 2 catalyst efficiency code hanging out in the permanent codes; I am going to replace both O2 sensors on that bank on Monday in the hopes that will resolve that. Worst case scenario, I replace the cat on that side. Fingers crossed! Thanks for the help resharp001!

 

Hopefully, that was it and clear sailing from here on out. Not sure I was able to help all that much, but it is nice when people who have torn these engines apart chime in. Unfortunately, I've gotten a good look inside this engine more than I would have cared to. I had a really nice couple weeks or so after rebuilding my timing.....everything was running well and then the next issue started.....won't accept filling with fuel . Time to solve that problem next.

 

FTIW -- we had the 0420 Cat Effy and Sea Foam worked.. so far.. cleared the codes, had to drive it over 100 miles to clear all modules for the PA emissions test.. It passed .. good for another year. BTW I did have 2 new O2 sensors for half cost of Mopar: NTK is the world’s largest supplier and manufacturer of original equipment oxygen sensors for nearly all vehicles on the road today. https://ngksparkplugs.com/en/product...oxygen-sensors

 

I bought those through my local NAPA, so I guess I'm on the right track.

I run NGK plugs in everything I own; I've had great results so no reason to change (except at specified maintenance intervals) ;-)