2017 with 60,000. Can’t really get a good video of the sound. Get a pretty aggressive loud tick for the first 5 or so minutes of a cold start. It’s not injector tick. Much louder. Goes away ALMOST completely after fully warm. I’ve listened to the rocker videos but my sound goes mostly away when it warms up. Is this an early sign of rocker failure? The sound is loudest when slowing to a stop as in a deceleration or when you rev the engine, and the rpm’s return to idle

 

It might be better to also record the sound with the hood open, phone near the top of the radiator or above the engine.

 

I'm having a hard time hearing it on the video....a few times I thought I could hear it faintly but I think the revving kinda starts to capture my focus and drown it out. What I would say is the rocker tick is very distinguishable. For example, I had the Jeep running and about 75' down the driveway when I called my wife out to help me troubleshoot a noise (unrelated to my rocker tick). She said "what, that ticking sound?" She doesn't know much of anything about cars but could identify that didn't sound right from a decent ways away.

What you might do is at idle, get that phone down around the passenger valve cover and head, and then the driver's side. That way you can also compare the noise side to side.

 

The 3.6L in 2012 has cold misfire issues which is the norm. I'm pretty sure they fixed some of that by 2017. I think you should get the Jscan app and watch your error codes for a while. JK Jeeps have had problems with the 3.6L management system OVER reacting with the cold misfires. Mine stops having misfires over 1000 rpm. I use the Jscan app to watch the misfire sensors for 2 4 6 cyclinders because there is a recall worthy issue in that driver's side head and especially with Cylinder #2. Jeep had a vendor that supplied sub par valve guides that really show up worse in Cylinder 2. I clear the misfire codes with Jscan after warm up so I have very little trouble because the computer doesn't put the engine into safe mode unless the random misfire code shows up (which it does often on cold start up). Safe mode will also kick in with high rpm driving if you have misfire codes from cold misfires which can kick off crank and cam sensor codes then your traction control kicks in as part of safe mode.

 

Also have the 2012 and have to agree. The CEL would come on and the cold idle was rough. Once the car warmed up I could clear the code and restart and no problem.

I changed coil packs, twice, plugs twice. O2 sensors, fuel injectors. Still happens. Now when on cold start I hold my idol over 1000 rpm till engine coolant reaches 150• (about 2-3 minutes), then let it drop to natural idol of 670 and no problem. But if I let the idol drop too early you can feel the misfire.

So at this point it appears it is a glitch in something that parts haven’t corrected (at least for me).

 

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I use the Jscan app to clear the codes if the cold misfires are detected and you can track the sensors for each cylinder to determine it is just cold misfires or idling misfires for Cyl #2.. The Driver's side head is bad and causes these misfires that are not really legitimate. P0300 is the code that kicks off the safe mode triggers traction control errors, cam and crank sensors and all of that keeps you from being able to accelerate past about 2k rpm. It is maddening that Jeep has not created a fix but they are making tons of tons of $$$$$ when Jeep owners continue to take the Jeep to the dealership and pay for fixes that are not needed.

 

Thank you all for the help. I’ve had the JScan app for a while, but it has never thrown a code. In person, it’s very audible. But like I said, it goes away eventually. The misfire theory sounds credible but the idle isn’t affected and drivability is completely normal, are there any other data feeds I can watch to see if anything is funky in JScan?. Maybe a bad injector? There is a local trusted Jeep shop I’m going to take it to soon. I have a third car thankfully.

 

All updates will be appreciated.. I could not hear it; my hearing is less than 100% ,, Have you (with an assistant) pulled plug wires when it was occurring ? 1 at a time and see if you can ID a cylinder. Based on your post you might get 1 side before it gets hot and stops.

 

I'd start by monitoring the misfire live data with jscan. When you get into jscan just click the live data button. click the 3 dots in the bottom right corner and simply search for misfire. put checks in the boxes for cylinders 1-6, hit ok and then hit the play button to start monitoring. That would at the very least rule that out, but I also think you'd start to see a bad injector show with a misfire too.

When I tore mine apart for the tick I was not 100% certain what I would find. It took a good bit of work just to get things torn apart and the whole time I was thinking I'd be pretty pissed if I got in there and didn't find a bad rocker. It was actually a relief when I did find one single rocker that was shot. I was in kind of a similar situation as you questioning things and figured I'd just start pulling things apart.....though mine is not a DD and I have plenty of other transportation options so having the jeep out of commission was not a big deal.

I know you have listened to plenty of videos already, but if it helps here is a direct comparison with my engine. This first video is before the repair and you can definitely hear what a bad rocker sounds like here -


This video is after the fix and even though this 3.6L is just dang ticky sounding in general, if you listen to one and then the other back to back you can definitely hear the distinguishable difference. I would note that this video sounds loud, but keep in mind that phone is right down there by the valve cover. If everyone filmed their 3.6L that same way I'm pretty sure it would sound loud too.

 

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