P0300 Code - New Cam Shaft?

[mfran12345]

Got a check engine light and it has the random/multiple misfire code P0300. Back in 2021 I had the computer flashed per TSB 18-024-21 but they did not replace the right cam shaft. I went to a dealer shop over the weekend and they said i need a new right cam shaft. But apprently the part is on nation wide back order. They have to wait for a manager to call Jeep on Monday to see what to do. They quoted $1k to replace. I’m outside my warranty as it’s 6 years old, 56k miles. Any chance it would be covered per the old TSB since I never had the right cam shaft replaced back then? Anyone else have this issue and got any advice? Thanks.

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[Lost1wing]

That was the reason for the TSB, I believe. They played kick the can with you and won. You can try and be nice and politely ask, reminding them that you had the issue before. That sucks man!

 

[yoda13]

I would at least explain and ask, but privately I wouldn’t expect much. On the other hand, $1000 was less than I was expecting, please don’t take this the wrong way, it’s a lot of money especially if you don’t think you should have to pay it.

 

[Hootbro]

Hopefully they will goodwill some or all of it though.

 

[ShadowsPapa]

Got a check engine light and it has the random/multiple misfire code P0300. Back in 2021 I had the computer flashed per TSB 18-024-21 but they did not replace the right cam shaft. I went to a dealer shop over the weekend and they said i need a new right cam shaft. But apprently the part is on nation wide back order. They have to wait for a manager to call Jeep on Monday to see what to do. They quoted $1k to replace. I’m outside my warranty as it’s 6 years old, 56k miles. Any chance it would be covered per the old TSB since I never had the right cam shaft replaced back then? Anyone else have this issue and got any advice? Thanks.

That TSB flash was only supposed to be done with a cam replacement.
It doesn't mean the cam was bad then.
I'd bet the cam was fine then and they were grasping at straws.
No way a bad cam went from 2021 until 2025 and you didn't know it.
You may need a cam NOW, but I don't believe you can connect 2021 to now.

 

[ShadowsPapa]

That was the reason for the TSB, I believe. They played kick the can with you and won. You can try and be nice and politely ask, reminding them that you had the issue before. That sucks man!

The TSB was for a flash that goes along with a new cam - likely a different profile.
It doesn't imply or mean the cam was bad, it was to resolve an issue.

No way a bad cam went 4 years from 2021 to 2025.

 

[Lost1wing]

I think they know what the problem is. I think the flash only slows down the inevitable. If the flash changes the parameters in which the engine goes into high lift, it is possible the OP caught this early. Maybe his driving habits are enough to make the cam last longer. I don't think Stellantis will ever come clean on this. Kick the can enough, it finally goes away.

I'm still hung up on, why mostly the right side. Direction of rotation? Oiling problems?

 

[Hootbro]

AFAIK, the PCM flash only widen the misfire count parameters before it would set the MIL.

 

[Lost1wing]

AFAIK, the PCM flash only widen the misfire count parameters before it would set the MIL.

So it basically keeps the cel from coming on. Kick the can!

 

[Hootbro]

So it basically keeps the cel from coming on. Kick the can!

Basically. To be fair though, the misfire count programming on the early models was not as tight as it should have been in my opinion.

 

[Lost1wing]

Basically. To be fair though, the misfire count programming on the early models was not as tight as it should have been in my opinion.

Maybe so, but most don't even get a misfire cel nor have cam issues. My point being, if the flash was to change the trigger (delay) for the cel, all they did was prevent someone from reporting the cel during warranty and then it's not on their dime.

To have a shortage on these replacement parts tells me one thing for sure, Stellantis has a problem.

So Jeep owners are saying that they had a tic with a cel and the dealership did a software upgrade. The tic had went away and the cel did not return. Down the road the tic came back with no cel. Dealer will not work on it without a cel and tell the owner that it soubds normal. The next return the tic is worse and now the cel light is on but it also runs like crap. Dealer says oh it's the cam and followers but you are out of warranty so it's on you, despite having previous history. I fell bad for people in these cases.

It's hard to believe that after a visit to the dealer with the tic and getting a flash, that only changes the parameters of the cel, to then drive away without a tic. Maybe just the words of "we have fixed it", was enough to also tune the owners ears?

 

[ShadowsPapa]

Maybe so, but most don't even get a misfire cel nor have cam issues. My point being, if the flash was to change the trigger (delay) for the cel, all they did was prevent someone from reporting the cel during warranty and then it's not on their dime.

It was triggering for misfires when there were not any misfires.
As far as a cam - once that thing is worn to the point of a misfire - it's not going to go far at all and there will be noise.

It was literally for preventing people coming in with a MIL for nothing at all.
A bad cam will show in other strange readings, and - a noise.
It wouldn't change how soon someone reported in with a cam issue. Other signs will be there.
A cam in a legacy engine can be really bad before a misfire will be felt or detected - they detect a misfire at the drop of a hat.
My 2022 reported a misfire - but the engine was running smooth as silk, not a wobble, you literally felt like everything was perfect in sound and feel and power - yet it detected misfires.
So - all they did was lessen the chances of a false report, they didn't lower the threshold for a true misfire. IF the cam is bad enough to cause a legit misfire - it's toast already.

The TSB didn't take away legit misfires at all. Only false misfire readings.
Bad cams would still be found at the same rate, and same point in time.
Worn intake cams are generally shown in odd O2 readings, the PCM compensates for the lower oxygen content - to a point. When it can't, there's a misfire. So - no, it wasn't kicking a can down the road.

 

[ShadowsPapa]

So Jeep owners are saying that they had a tic with a cel and the dealership did a software upgrade. The tic had went away and the cel did not return.

the TSB couldn't possibly make a tick go away. If it's worn to the point of a tick, that tick is there forever. How can a PCM change make a physical sound of worn parts go away? Ticks don't just go away.

 

[Lost1wing]

the TSB couldn't possibly make a tick go away. If it's worn to the point of a tick, that tick is there forever. How can a PCM change make a physical sound of worn parts go away? Ticks don't just go away.

That's right! That is why I think the flash was not only for cel parameters. Maybe the oil pressure or phaser also got an update. IDK!

It happens though. People have a tic, get an update and drive away. If I had a tic after an update, I would turn right back around and tell them that the tic is still there. Yet people are saying the tic is gone, for now.

We have already discussed other reasons for the tic. The flash won't fix a bad coil, sparkplug or injector either. So the flash is to "kick the can down the street" if it only changes the cel parameters. Early diagnosis of a p0300 and right side misfires would be a better plan.

 

[ShadowsPapa]

Maybe the oil pressure or phaser also got an update. IDK!

Oil pressure didn't change, and even if it did, it won't change a physical tick due to wear.
It's still, from day one, regulated at the same pressures, and the high volume solenoid kicks the oil pump into high at the same RPM.

Phasers only handle cam timing, not the valve lift. you can advance or retard the intake valve timing, but the physical parts still do the same job with the same wear.
If your LP has a bad spot in a groove, you can rotate it on the platter, but it's still going to come under the stylus. You just changed when, not how.
(I watch the oil pressure as well as other engine and vehicle indicators fairly closely - and have on all of my vehicles. It's why I have the rally gauges in my SX4 and the AMX cluster in my Javelin)

the update can't make a tick go away. It's simply impossible. There's nothing a PCM can do to make physical damage disappear. If you arrive with a tick, you leave with a tick. It doesn't matter what people say - could be a placebo effect, hey, I don't notice it now - but it will still be there because you can't alter physical damage with software.
30 psi is more than enough for an idling engine. 20 is plenty for idle for that matter, even for a larger engine with a lower volume pump. Pressure doesn't lubricate valve train parts. 10 psi will send oil shooting over a fender.

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