Flashing engine warning light

[Snook]

I don't know as the 2022 models are totally free of the issue. My 2022 has already had one flash at a little over a thousand miles on it, without any sort of running issue or problems. It did it on a startup, and has not done it since. It was a P0300

Did the flashing light go off after a short time? Mine did. The engine never ran rough.

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[WetWilly]

Did the flashing light go off after a short time? Mine did. The engine never ran rough.

Yes, I was only 6 miles from home. By the time I drove home it was off. That was about 300 miles ago. If it had any kind of a hiccup it was undetected by me. It ran fine. KNOCK ON WOOD with crossed fingers

 

[Snook]

Just made it back home (650 miles). No issues or CEL’s. Once again the Gladiator proved it a great towing platform. Averaged 13.8 mpg. I’ll keep you updated on the CEL issue, I’m sure it will be back.

 

[WetWilly]

Just made it back home (650 miles). No issues or CEL’s. Once again the Gladiator proved it a great towing platform. Averaged 13.8 mpg. I’ll keep you updated on the CEL issue, I’m sure it will be back.

Glad you got back without issues.

 

[Snook]

They usually don't go away - but I have seen them go away.
With the gladiator - it's all too often a cam/rocker issue.

I appreciate your wisdom on these issues. after driving back home from FL on Friday (600+ miles) with no CEL I’m not sure at this point what I can do other than wait for it to happen again, if it ever does. As we got closer to home I did push it more than I usually do, bringing it up to 3k rpms and holding it there but got no CEL.

in Your experience, how has this cam rocker issue been resolved? Replace them, replace the entire engine?

 

[jebiruph]

I appreciate your wisdom on these issues. after driving back home from FL on Friday (600+ miles) with no CEL I’m not sure at this point what I can do other than wait for it to happen again, if it ever does. As we got closer to home I did push it more than I usually do, bringing it up to 3k rpms and holding it there but got no CEL.

in Your experience, how has this cam rocker issue been resolved? Replace them, replace the entire engine?

There is some threshold for the number of misfires that occur before the error light comes on. When I was getting P0300 errors, I used a OBDII BT adapter and Jscan for real-time monitoring of mis-fires. This made it obvious when it was finally fixed as even the random mis-fires that weren't triggering an error went away.

 

[Snook]

There is some threshold for the number of misfires that occur before the error light comes on. When I was getting P0300 errors, I used a OBDII BT adapter and Jscan for real-time monitoring of mis-fires. This made it obvious when it was finally fixed as even the random mis-fires that weren't triggering an error went away.

how was it fixed? Did your vehicle run bad during the time prior to the fix?

 

[jebiruph]

how was it fixed? Did your vehicle run bad during the time prior to the fix?

Sometimes, but other times mis-fires would occur without running bad. Here's my live monitoring thread.

https://www.jeepgladiatorforum.com/forum/threads/live-data-monitoring-with-jscan.55262/post-904912

The fix was the TSB for the odd cylinder intake camshaft replacement followed up with a cam phaser replacement. I have various related posts in this thread https://www.jeepgladiatorforum.com/...r-those-with-misfire-issues.24853/post-895085

 

[Snook]

Sometimes, but other times mis-fires would occur without running bad. Here's my live monitoring thread.

https://www.jeepgladiatorforum.com/forum/threads/live-data-monitoring-with-jscan.55262/post-904912

The fix was the TSB for the odd cylinder intake camshaft replacement followed up with a cam phaser replacement. I have various related posts in this thread https://www.jeepgladiatorforum.com/...r-those-with-misfire-issues.24853/post-895085

thank you for sharing!

 

[Snook]

Since I haven’t had an issue since the FL trip, was wondering if I should go ahead bring it by the dealership here? Not sure what they could do since I haven’t had another CEL yet.

 

[ShadowsPapa]

I appreciate your wisdom on these issues. after driving back home from FL on Friday (600+ miles) with no CEL I’m not sure at this point what I can do other than wait for it to happen again, if it ever does. As we got closer to home I did push it more than I usually do, bringing it up to 3k rpms and holding it there but got no CEL.

in Your experience, how has this cam rocker issue been resolved? Replace them, replace the entire engine?

No need to replace engine, just the offending parts.
Cam, rockers/followers, lash adjusters (some still call them lifters), perhaps the VVL solenoids (which control oil to the lash adjusters for the intake valves)
Oil pressure supplied via the VVL solenoids through the lash adjusters to the rockers keeps the lock pin retracted so the high lift portion of the rocker or follower isn't in play and it stays in low lift mode.
If either the solenoid has a problem, or the wrong lash adjusters are used, no oil pressure is there to retract that lock pin, the pin move out and holds the high lift part of the rocker up to contact the cam and the thing is in high lift mode.
Imagine some cylinders being in low lift and others in high lift mode all at the same time.
Plus - the thing is only on the rollers in low lift mode - below 2,800 rpm. High lift mode, which they assume won't generally be used except when power is needed, for short times, it's more like a flat tappet setup. You get a lot more wear (but even at that, it makes me wonder how the heck I'm running a flat tappet 4.0 with a Comp xtreme energy cam, MOPAR performance valve springs and modern oil and not having any wear problems while these things are trashing cams!)

Here's the thing with a misfire reported by the PCM via CEL - misfire has broad meaning.
And an intermittent misfire may not trigger a CEL or even set a DTC. (see log below)

A misfire can simply mean abnormal burn, or worse.

Log from a Jeep 3.6 that had a misfire so bad that it felt like a bucking horse - I mean it jerked and jumped as you drove it and it wasn't just a cylinder not hitting and pulling its weight, it was like it was fighting the others, and yet - check out that the system said about it......
The dealer found no DTCs stored, the CEL was not on, and never came on. It ran so rough - not constantly, but pretty bad, I was concerned about making it to the dealership. But by the time I got 2/3 of the way there, it smoothed out and ran like a champ. Note the line about the MIL (Malfunction Indicator Lamp) - 0.00 miles because it was never requested for this, or anything else prior.


2021/01/04 11:52:06.281
Faults found.
P0303
Error code: P0303
Cylinder 3 ignition failures
Test not complete
Error intermittent
Error warning lamp not requested
CARB Freeze Frame:
___________________
Fault code: P0303
PCM Mileage since MIL On: 0.00 miles
PCM Odometer: 950.27 miles
Open Loop - Bank 1: No
Closed Loop - Bank 1: Yes
Open Loop due to Driving Conditions - Bank 1: No

So, what can be called a "misfire" by the PCM can be so subtle you don't feel it and in fact, you'd say it never misfired, or it can buck like a horse with a bur under the saddle, and never set the MIL.
It's a broad term pretty much meaning an imperfect burn, IMO.

In Jerry's case, and even some of the other cam issue cases, that imperfect burn is due to valving issues causing either too much or not enough intake - since these are not direct injected, any time the valve timing or lift is messed up, it impacts the air and the fuel.
At lower RPM, they want the air speed to be kept up to keep turbulence in the chamber and if the valves are stuck in high lift mode, it's going to be like my car with a lumpy cam. Rough running at lower speeds.
The long intake runners and low valve lift help low RPM torque and the turbulence of the fast moving air coming in helps prevent detonation. But open the valves wider at lower RPM, the air moves slower going in.

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