So there is alot going on with my issue, so here is a quick summary if you don't want to read my novel below....
--TL/DR --
I have a 2018 Wrangler JK with the 3.6L engine just coming up on 39k miles. Ive been dealing with a P0340 cam shaft sensor error that wont go away, despite everything else running smooth. All trouble shooting, replacing sensors, wiring, even replacing the PCM, etc all failed to clear the code - I finally took it to the dealer, and after 6 weeks of working on it and not finding a solution the dealer now says i need a new engine because they cant find any reason why the code is coming up.

When asking how they came to the conclusion a whole new engine is needed to fix a simple sensor, i was given a BS excuse it could be a problem 'deeper' in the engine and they suggested i just drive it was a 'nuisance' check engine light on and to just ignore it as the engine was running fine, sounded great, and pressures/temps/levels all tested fine when manually checked. Only after refusing that to be a solution, and wanting a reason why replacing the entire engine could fix it - they came back and now magically there is a knock that just happened to start forming from the bottom end when they were trouble shooting. They were very open that the bottom end noise was NOT there when it came in, it was NOT there the 3 different times they tried to get me to take the car back with the P0430 nuisance error, and assured me the engine sounded and tested great it just was throwing the false P340 error. The mention of a bottom end knock only came up when i pushed for a reason why i needed an engine replacement to fix a simple sensor error, and most importantly that they WILL NOT do any bottom end crank work and only replace the entire block when that happens. If the issues were not present when i dropped it over, never came up once during trouble shootings, and only got brought up as a reason my engine needed replaced... do i have any course of reaction? They want me to pony up $18k for a reman and said that's the best they can do..... but also cant explain why a bottom end knock would cause issues with a top end cam sensor (suspicious as fuck!)

--If your interested, here is the store with a bit more details --
So i've been through the RINGER with my 2018 JK that all started with rocker/lifter noise that started around 38k. Warranty was up and since I did all the service my self up to this point (all of a whopping 5 oil changes that is) they refused to good-will it and said i had to come out of pocket.

I was recently laid off and had time on my hands, so i decided to do the work myself and picked up a beater to drive in the meantime. After a very long winter full of minor hiccups, i finally got it all back together but have been dealing with this one last cam shaft position sensor error (P0430) which is the passenger side exhaust cam. I finally reached my limit, and had it towed to my local reputable large Jeep dealer and paid the $200 diagnostics fee. After about 5 minutes, they came back and said it was a bad sensor and that needed replaced - shocker which did not fix the issue. They checked wiring, even made a jumper and ran that to the PCM to rule out any wireloom issues, and still no change.

At this point, they claimed it could be something with the rockers/lifters and said they would need $4500 to open it up and replace all rockers/lifters/and all 4 cam shafts. I was not OK with that, but i did use aftermarket rockers/lifters so I approved them going in, opening it up, replacing rockers and lifters to ensure we had high quality OEM ones in there that didnt have the collapsing issue they are known for, and since we were already in there with sunk labor costs lets replace the one cam that was giving us issues since it was only $280... but to stop there and contact me open it was open to view any wear on the other cams and make a decision before doing any work. They said their master tech (who does all the rocker/lifter replacements) would be putting me on the rack soon and would call that day once its open to discuss options and go from there.

Well, they never called or responded back to my calls, and 5 days later the service advisor called to say it was all done! They didnt replace any cams as the tech said they all look beautiful, the engine was quiet and running well, but there was still that "nuisance" light on but the techs assured him it was fine to drive. By nuisance light he means the check engine light with the P0430 error that never went away. What happened to replacing the passenger exhaust cam shaft throwing the error and calling me? He said his guy said they all looked great, no scoring, pitting, wear marks, nothing - so they don't need replaced. My big question was the tone wheel thats pressed on the cam shaft that the sensor reads, we replaced everything in the circuit except that - which i dont have the ability to scan and read the sign waves and know if they are correct or not and hence why i was willing to toss the $280 at it just to make sure.

I told the advisor that was NOT acceptable to just take the car with a check engine light and call it OK, and a few days later and claimed after testing everything with manual gauges all the pressures, reading, etc were great but the PCM could be misinterpreting them so they were going to replace the PMC under warranty and got me a rental. FOUR WEEKS later i finally hear from them and the PCM didnt fix anything and they were just at a loss as the techs called it a real "head scratcher". At this point their only suggestion was to replace the entire engine as there may be an issue deeper inside that's causing this false error and again suggested to just ignore the light and drive it if i didnt want to replace the engine. WHAT?? The circuit is fairly simple, and just throwing random parts at it is not diagnosis - and now saying i need a new engine but not giving any real reason was a cheap way to pass the buck. After the constant lies, lack of communication, misleading information, and BS - I was done working with this service advisor and now for the FIFTH TIME i needed to speak with the service manager.

Finally, the service manager calls me back and is just shocked whats going onbut assured me he would take it up personally and get back to me the next day. The following day, the service manager comes back and says that now there is a knock in the bottom end, and they don't service crank issues and thats why I needed a new engine. I was shocked, there was no bottom end knock when i took it in for service, no mention of a knock over the last 6 weeks you had the car, and only now you say that? The service manager admitted that the knock wasn't there when it came in, but the more they did trouble shooting, trying different things, and test driving the car did the knock start to come up. None the less, the P0340 error was still present, and even if we had a spun bearing or rod knock - that wouldn't cause that error anyways so it doesn't make sense.

The service manager agreed to go back in and replace the cam shaft with no labor charges and we will see if the code goes away and if the bottom end knock is resolved. I guess I'm just at a loss as to what i should do?? I brought the car there with no bottom end knock, they spent 6 weeks dicking around with it trying to figure out what's going on, and then when they cant find a solution and try to claim i need a whole new engine this magic knock appears at the very end and is the excuse as to why i need a new engine. I haven't been there in person to hear it, so hope they were just saying that to get me to OK a new engine.... but lets say the new cam shaft doesn't fix the P0340 error and we have an engine knock (that they openly admit was not there until they kept messing with it) what are my best course of action?

I know that is alot to read, but i wanted to pass along as much as i could to show the interactions with the dealer and the round about way they came to the conclusion i need a new engine. Most importantly, there was no knock when i brought it in and was assured multiple times the engine was running great, had no top or bottom end noise, and it was just an erroneous error they were chasing down - but i dont see how that could have happened and now im on the hook for a $20k repair bill.

Any advice, guidance, or personal experience is welcome - thanks again everyone for all the help!!

 

I don't know much, but can the two cam shaft sensors be swapped around? And, I would ignore any knocking sounds until the motor blew up.

 

I really don't have constructive advice here, but reading this all makes me very sad and angry. The valvetrain issues on this 3.6L are such a cluster F and it's so hard to find help with it. Compounding the frustrating is that even when you get to the point of going to a dealer, they are just not in the business of REALLY troubleshooting stuff. They do the few steps the service manual is telling them to do and then they throw their hands up in the air and say "it needs a new engine". it's the same reason that someone rolls in with some busted R&P teeth and they say "this jeep needs a new axle, gonna be $3500". These techs are programmed to follow the manual and swap stuff in/out. There are a few folks out there in YouTube land that I've seen doing real work on this 3.6L valvetrain....looking at the actual pulsation of signals n stuff and it's pretty interesting to see. I found a lot of that diving down the rabbit hole of the actual tool they use to measure if the tone rings had shifted.

I've dealt with cam related code for several years so i feel the pain and aggravation that this sort of thing creates. in this current scenario, i really don't know what i'd do. i really don't think the dealer, or really any CDJR dealer, is capable of actually resolving the issue, so in a sense it's like squeezing blood from a turnip outside of paying for an engine replacement.....which seems completely and utterly absurd.