Need Help With Wife's Jeep Wrangler

mysticsvt

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"Anything under the sun"...we shall test that statement.

Before I have to go join a Jeep Forum I'll ask my fellow Ford enthusiasts. So any help is greatly appreciated here.

So she has a damn near mint 2016 Jeep Wrangler, no mods, babied and 36,880 miles. The only thing I have done to it is change the battery out last week due to a dead cell.

Today she tells me her check engine light came on and when I checked the code it was a P0304 or misfire in Cylinder 4. Now it's my understanding this could be an air leak, bad coil pack, spark plug, head, bad fuel, gas cap lose or pretty much anything that has to do with the combustion chamber on cylinder 4. When I did my engine visual I noticed her coolant level in the overflow tank was at the very bottom, not good. Now I have thoughts of a blown head gasket. The level in the radiator was fine, not milky. Other than checking the gas cap, airbox for leaks I swapped #4 and #6 coil pack to see if I got a swap in code to P0306. I had also disconnected the batter before doing so. Reconnected the battery and started the vehicle up, seemed normal as before. Drove 5 miles and to be seemed normal with a small notice of shake around 1K. The check engine light never came on nor did any code when I ran them, just "Done" which means no codes on the self diagnostic test the Jeep has. I would have pulled plugs for a visual but from a video I watched this guy took have the engine apart to get to them, not ready to do that just yet. I told her to drive it normally tomorrow and look for any difference is sound, vibration or power. If the light comes on let me know asap. I will also contact the dealership but as we are JUST out of our warranty(of course) not sure what they will do.
Like I said thanks for any help which is greatly appreciated and apologies it isn't a Ford. She likes her Jeeps...3rd or 4th one in a row. -Shane
 

derklug

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Older ones had issues with the valves, but at your mileage I would suspect a coil.
 

nxhappy

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shit. It could be the cylinder head. pretty common from what I hear. first, install a new plug and coil. If THAT doesn't fix it, more than likely the head is bad.
 

CV355

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Dang, I had a coworker who had the same exact problem with his '17 Wrangler. I'll text him and see what it was, but head/ head gasket issue sounds about right.

The only problem we had with our '16 JKU was when it got hit head on at 100mph... Thing saved my wife's life, so I have to give it that...
 

scott9050

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Good luck. My 7500 mile 19 Jeep Cherokee with the 2.0 Turbo died at 70 MPH taking the steering and brakes with it and leaving me stranded 7 miles from the nearest town and would not restart. Had it towed to Jeep dealer, they replaced the start/stop relay which was blown with no change. Dealer told me that there were multiple codes stored and they got FCA involved classifying it a star case on day 2 because they had no clue what was going on. Dealer then changed the fuel pump relay (bad) and fuel pump, still a no start. I am now on day 8 of this saga with no end in sight.
 

mysticsvt

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Good luck. My 7500 mile 19 Jeep Cherokee with the 2.0 Turbo died at 70 MPH taking the steering and brakes with it and leaving me stranded 7 miles from the nearest town and would not restart. Had it towed to Jeep dealer, they replaced the start/stop relay which was blown with no change. Dealer told me that there were multiple codes stored and they got FCA involved classifying it a star case on day 2 because they had no clue what was going on. Dealer then changed the fuel pump relay (bad) and fuel pump, still a no start. I am now on day 8 of this saga with no end in sight.
Ouch, good luck with that man.
I topped off her coolant this morning and sent her packing. She drove 45 minutes to work in traffic and at highway speeds and nothing. I'll keep an eye on her coolant level and she knows to keep me informed of any irregularities. There is apparently a flash due on her Jeep for just such things....hmmm.
 

Evil Bender

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For what its worth ,on every jeep I have ever owned bad coil packs would act up when they got hot . Also did you pull the plugs and check for coolant burn ?
 

mysticsvt

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For what its worth ,on every jeep I have ever owned bad coil packs would act up when they got hot . Also did you pull the plugs and check for coolant burn ?
I did not, I would have but it seems plugs on a Jeep are really hard to get to and this was after I got home at 1030PM. I figured after a 12 hour workday I had enough in me to look the engine over and swap two coils packs to see if it moved to 6. Normally, it would have been the first thing I did. After watching a video the guy had removed about 20 items before he even got to the plugs...what they hell.
 

mysticsvt

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best wrangler on the planet is the 97-2004 TJ. Got 258,000 mileson mine. all original. runs like a top.
Have you been watching Designated Survivor? Man, he has gone downhill in roles since Lost Boys! haha
 

mysticsvt

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There is a coolant test kit that will tell you if you have exhaust in your coolant.
https://www.amazon.com/Block-Tester-BT-500-Combustion-Leak/dp/B06VVBSFTF/

Before you do that though. Move the coil on that cylinder and see if the misfire code moves. If it does it's a bad coil.
Thanks, I did that last night soon as I got home. Moved 4 to 6 and reset it. So far it has not come back. Topped off coolant this morning and will keep an eye on that.

**Just ordered the kit, thanks again. **
 

RedVenom48

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"Anything under the sun"...we shall test that statement.

Before I have to go join a Jeep Forum I'll ask my fellow Ford enthusiasts. So any help is greatly appreciated here.

So she has a damn near mint 2016 Jeep Wrangler, no mods, babied and 36,880 miles. The only thing I have done to it is change the battery out last week due to a dead cell.

Today she tells me her check engine light came on and when I checked the code it was a P0304 or misfire in Cylinder 4. Now it's my understanding this could be an air leak, bad coil pack, spark plug, head, bad fuel, gas cap lose or pretty much anything that has to do with the combustion chamber on cylinder 4. When I did my engine visual I noticed her coolant level in the overflow tank was at the very bottom, not good. Now I have thoughts of a blown head gasket. The level in the radiator was fine, not milky. Other than checking the gas cap, airbox for leaks I swapped #4 and #6 coil pack to see if I got a swap in code to P0306. I had also disconnected the batter before doing so. Reconnected the battery and started the vehicle up, seemed normal as before. Drove 5 miles and to be seemed normal with a small notice of shake around 1K. The check engine light never came on nor did any code when I ran them, just "Done" which means no codes on the self diagnostic test the Jeep has. I would have pulled plugs for a visual but from a video I watched this guy took have the engine apart to get to them, not ready to do that just yet. I told her to drive it normally tomorrow and look for any difference is sound, vibration or power. If the light comes on let me know asap. I will also contact the dealership but as we are JUST out of our warranty(of course) not sure what they will do.
Like I said thanks for any help which is greatly appreciated and apologies it isn't a Ford. She likes her Jeeps...3rd or 4th one in a row. -Shane
You guys should still be well under the powertrain warranty. 5 year, 60000 miles. A 2016, even if purchased fall of 2015 should still be covered.

Take it in, describe issue and tell them to call you when its ready.
 

BlckBox04

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You guys should still be well under the powertrain warranty. 5 year, 60000 miles. A 2016, even if purchased fall of 2015 should still be covered.

Take it in, describe issue and tell them to call you when its ready.

this
 

jeffh81

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You guys should still be well under the powertrain warranty. 5 year, 60000 miles. A 2016, even if purchased fall of 2015 should still be covered.

Take it in, describe issue and tell them to call you when its ready.

Or better yet. Take the busted bitch in and walk out with a new Gladiator and give us a full review of it :cool:
 

mysticsvt

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Or better yet. Take the busted bitch in and walk out with a new Gladiator and give us a full review of it :cool:
HAHAHAHA...don't go putting GREAT ideas into my head! But no....I paid my wife's last Jeep off (5K) to be rid of the payments and she traded it in for a new Jeep...lol. She owes like 3 on this and it's mint so no. LOL
 

mysticsvt

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Or better yet. Take the busted bitch in and walk out with a new Gladiator and give us a full review of it :cool:
HAHAHAHA...don't go putting GREAT ideas into my head! But no....I paid my wife's last Jeep off (5K) to be rid of the payments and she traded it in for a new Jeep...lol. She owes like 3 on this and it's mint so no. LOL
 

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