My turn for some P0300

[WilldWilly]

Pulled into work yesterday and truck seemed to run rough. Really rough. I was turning at the time, and thought it felt similar to the front axles binding as they do in 4wd at low speed. But it was far worse, and the CEL started flashing as I pulled into my space. I knew it was a misfire at this point, so I shut it off for a few seconds, then turned it back on. CEL was gone and it seemed to run smooth. A few seconds later the misfire started coming back along with a steady CEL. After work, I started the truck and drove it to AutoZone since my code reader is in a car under 2 feet of snow. P0300 was the only code that popped up. So over to the dealer I went. The service writer checked the code, checked my vin and gave me wonderful news. Seems my Powertrain warranty expired on the 21st of January. Just 6 days ago with only 46k miles on it. Now I am hoping for a cam sensor failure, or bad gas. At least the cost is on me anyways, and more reasonable. I am sure if they need to go internal, it is going to hurt.
My wife was on the internet digging for the culprit. I finally told her she is wasting her time. At one point she mentioned a loose gas cap. I just laughed. So hopefully it will get diagnosed sometime next week, and parts for whatever it is will be available. I thought about calling Jeep, but today no one cares anyways, so it would be a waste of time. People seemed to find it hard to get things covered when they are under warranty. Six days out, and I will be told to pound sand. I thought about buying a new one, but it has no trade in value. Less than half of new. And to buy a new one, I would have to by a lesser model to stay at the same price point this one was when new since the prices shot up over the past couple years. (Mine is a loaded Willys) Thought about another truck, but I ruled that out quickly as I bought the Gladiator because of what it is. So now I wait to find out how painful it will be to fix, and move on to many more years with it.

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[Pickle_Bill]

https://amw4x4.com/collections/conversions/products/amw-405-hemi-345-8hp75-conversion-1

 

[ChrisNLA]

I'm still another month or two out from P0300 season.

I figure by March the weather will be right that I can drive from the house to town (well the other town), 35 minutes, park, run inside the Home Depot for ten minutes, come back out and get in the truck and almost definitely get a P0300 if the weather is between 60-80*

But the good news is, it's definitely not a cam for me

 

[MPMB]

Did you get a cylinder indication, or just a general fault? If you have cylinder info, then you'll know which side, or if it's all cylinders.

Worst case (and unlikely scenario) is new engine.

Likely case: Intake cam & rocker replacement. Self-performed repair: <$1000.

Lucky case: bad gas, bad plugs/coil packs, sensors off, etc. (run searches or read the "I'm done with Jeep" thread for starters)

Spoiler: Rough process of replacing right intake cam.

Rough outline (I don't remember all the deets, but you can search the site and find more detailed steps and accurate info) -

I replaced my cam and rockers myself. The hardest part is disassembling the f**king electrical connections to get the valve cover off. The kit is <$500, and there are a few specific tools you'll need. Cam sensor block and timing tensioner tool kit - $150 for the legit one. You can get the cheap AMZN one for $17 for the blocks (just plastic), and then find the correct timing chain tensioner tool, which is ~$50. Then a big socket (37mm or 39mm? I forget) for the cam phasers. Quality torque wrench for oof-dah (100ft/lbs+) and a smaller one for the cam bearings. Maybe a big allen for spinning the crank to DTC, or a socket will work.

Disconnect battery. Drain oil and coolant.

Strip everything that's over the valve cover (PCV on the back of the right bank is a bit of a PITA) and the airbox. Pull coil packs, sensors, cover, and install the cam phaser blocks (trim them with a knife to fit, it's ok). Slip the tensioner tool in to release the chain enough to remove from cam phasers (critical operation, but simple). Replace rockers, cam, seals, and gaskets, and reassemble.

I did it with the battery in, some take it out for extra room to work.

Put in fluids. Pray and fire it up. But seriously.

Let it cycle a bit. Change oil and filter again, in case metal is kicking around. Maybe change it again sooner than what the truck tells you.

Good luck.

 

[WilldWilly]

Did you get a cylinder indication, or just a general fault? If you have cylinder info, then you'll know which side, or if it's all cylinders.

Worst case (and unlikely scenario) is new engine.

Likely case: Intake cam & rocker replacement. Self-performed repair: <$1000.

Lucky case: bad gas, bad plugs/coil packs, sensors off, etc. (run searches or read the "I'm done with Jeep" thread for starters)

Spoiler: Rough process of replacing right intake cam.

Rough outline (I don't remember all the deets, but you can search the site and find more detailed steps and accurate info) -

I replaced my cam and rockers myself. The hardest part is disassembling the f**king electrical connections to get the valve cover off. The kit is <$500, and there are a few specific tools you'll need. Cam sensor block and timing tensioner tool kit - $150 for the legit one. You can get the cheap AMZN one for $17 for the blocks (just plastic), and then find the correct timing chain tensioner tool, which is ~$50. Then a big socket (37mm or 39mm? I forget) for the cam phasers. Quality torque wrench for oof-dah (100ft/lbs+) and a smaller one for the cam bearings. Maybe a big allen for spinning the crank to DTC, or a socket will work.

Disconnect battery. Drain oil and coolant.

Strip everything that's over the valve cover (PCV on the back of the right bank is a bit of a PITA) and the airbox. Pull coil packs, sensors, cover, and install the cam phaser blocks (trim them with a knife to fit, it's ok). Slip the tensioner tool in to release the chain enough to remove from cam phasers (critical operation, but simple). Replace rockers, cam, seals, and gaskets, and reassemble.

I did it with the battery in, some take it out for extra room to work.

Put in fluids. Pray and fire it up. But seriously.

Let it cycle a bit. Change oil and filter again, in case metal is kicking around. Maybe change it again sooner than what the truck tells you.

Good luck.

No specific cylinder, just the blanket code. Seems to be running ok now. Was it a glitch, or a tell tail something is starting to fail? I have had bad fuel set a 300 code before, so maybe some moisture in the fuel? Who knows?

 

[WilldWilly]

https://amw4x4.com/collections/conversions/products/amw-405-hemi-345-8hp75-conversion-1

I deserve that. Those who know, know. I would love a Hemi conversion. Maybe once the truck is paid off, I will do it.

 

[Fpolanco]

I recently got the P0300 series of CEL (I think it was P0306 to denote the misfire was cyclinder #6). I didn't know my ass from my elbow and decided to tackle this myself. I swapped out all of the ignition coils and spark plugs.

Looking back, it wasn't bad. The worst of it was doing it outside in December (I'm in PA) and having to work around my wife's work schedule (we have 2 little ones).

If you decide to go this route, check to see if you have a leak around the VVT solenoid. If so, order yourself some new gaskets so you have those on-hand. You have one in front of ignition coils 1 and 2.

Overall, the work wasn't bad. Just long. Could take most anyone between 4-6 hours if you're not battling the elements. Took me closer to 8-10 just b/c I had to remember where I left off and bringing my tools out and back in.

 

[Hootbro]

Maybe talk to them about a "Goodwill" repair submittal?

 

[WilldWilly]

Maybe talk to them about a "Goodwill" repair submittal?

I mentioned it, but they just looked away. I expect nothing from people, so no big deal. I just got a "that sucks" from the writer.
I did take it home since they could not tell me when they could look at it, as they were way to busy, yet three techs were just hanging out in the service isle shooting breeze with the service manager. Nothing work related. I figured since they were so busy, I would just take something off their plate.
I did use a tech 2 and did some data logging. All the values seem to be fine both at idle, and under load. I cleared the code, and so far after several restarts, 300 miles both city and highway driving conditions, it has not come back. If it comes back it will not go to jeep. That was a waste of time.
Funny how so many people call the 3.6 reliable, yet since this, I have found story after story of people with multi misfire codes on the 3.6. with everything from bad gas to cracked heads.

 

[WilldWilly]

I am not sure what the problem if any was, but I fixed it.

t.

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