P0303 Question

[Greg8444]

2012 5.7L with 117k miles. Replaced the plugs only, no coils, last fall, around 15k miles ago.

Recently it's started throwing a P0303 (cylinder 3 misfire). It doesn't throw this code while driving "normally" but it will happen when going uphill or under harder-than-normal acceleration (I'm not a leadfoot unless I'm in AZ in a rental Challenger). It's ALWAYS the #3 cylinder.

Assuming it was the coil pack, I replaced that but it's still doing it. I supposed it's possible I got a bad coil pack. I suppose it's also possible that one of the plugs went bad. But both those scenarios seem unlikely.

I do have AlfaOBD, if there are any better diagnostic tools than just the standard app that came with the OBD dongle I bought.

I've heard something like this could be an early indication of cam failure (I really hope that's not the case). The fact that it's always the #3 cylinder makes me thing it wouldn't be a cam/crank sensor.

Any thoughts on what else might be going on? I have an appt at my local shop on Monday, but I'd like to have a better clue before going in there.

Thanks in advance.

 

[Burla]

Cam lob under #3 is wiped, just gonna keep getting worse. It is a known issue.

 

[Burla]

most of the time happens this way, under load you get the misfire, but more and more it will happen w/o load.

 

[Greg8444]

Any idea how much time I might have? Gotta figure out a plan- crash it, trade it, rebuild it or put in a crate motor.

It's been going on for a few months, less than the last oil change around 3800 miles ago. It doesn't always do it under load yet, just sometimes.

 

[Daw14]

If you were to pull your valve cover off and observe #3 rockers , you will see that there is far less movement when the engine is rotated . You could let that help in your decision,as the lost material is swimming in your oil.

 

[Burn2k12Ram]

Any idea how much time I might have? Gotta figure out a plan- crash it, trade it, rebuild it or put in a crate motor.

It's been going on for a few months, less than the last oil change around 3800 miles ago. It doesn't always do it under load yet, just sometimes.

Jasper Reman motor and will be better than just a stock new motor. Is what I would do.

 

[Greg8444]

Any guess what the cost would be? I'm in St. Paul, MN, so labor is likely to be absurdly high.

 

[Greg8444]

Jasper Reman motor and will be better than just a stock new motor. Is what I would do.

​

Any guess what the cost would be? I'm in St. Paul, MN, so labor is likely to be absurdly high.

 

[Daw14]

I’ve heard some lees then good things about jasper’s . There are a lot of crate Mopar engines . This member may work for them as much as he is singing their praises. I might be way off too. Do your due diligence.

 

[Burn2k12Ram]

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Any guess what the cost would be? I'm in St. Paul, MN, so labor is likely to be absurdly high.

I do not work for them by any means. What I like is they stand behind their work by offering a great warranty even for the labor. I bought Ram that had the reman engine installed and I talked to the shop that did it and as stated on Jasper website they will honor the transferable warranty should a problem arise. That for me is a piece of mind. The paperwork shows $8500 total for Engine and Labor.

 

[Burn2k12Ram]

I’ve heard some lees then good things about jasper’s . There are a lot of crate Mopar engines . This member may work for them as much as he is singing their praises. I might be way off too. Do your due diligence.

Just curious what issues have you seen with the Jasper Engines?? I by no means work for them lol I just happened to purchase a Ram that has one installed. And am very pleased with it. Am sure there are other good options as well just going off what I have. I like the fact the parts and labor warranty and is transferable. That tells me a company stands behind their product.

 

[Burla]

Jasper Warranty

Find a local jasper recommended shop and a complete, you will also get a 3 year 100k warranty on parts and labor. Sounds good to me.

 

[Greg8444]

From what I've looked at so far, Jasper seems to be around 50% higher in price than almost everything else out there. So, I'm wondering if they're that much better? The transferrable warranty is nice for sure, but if I dump $5800 plus labor on a motor, I'm probably not selling the truck any time soon.

 

[Burla]

Check the oil control valve, this is what the dealer uses to detect if your engine can get a cam swap or needs to be replaced, if there is metal shavings all over this valve, get a new engine, whatever brand suits your fancy. If no metal shavings, consider the risk of a cam swap- before the latest crisis it was usually 3800 out the door with a new cam/lifters and surrounding parts. They don't have to remove the engine. Anyone's guess what this will cost now, maybe 5k. I imagine engine swaps have also gone up 20% plus or better.

 

[Greg8444]

Check the oil control valve, this is what the dealer uses to detect if your engine can get a cam swap or needs to be replaced, if there is metal shavings all over this valve, get a new engine, whatever brand suits your fancy. If no metal shavings, consider the risk of a cam swap- before the latest crisis it was usually 3800 out the door with a new cam/lifters and surrounding parts. They don't have to remove the engine. Anyone's guess what this will cost now, maybe 5k. I imagine engine swaps have also gone up 20% plus or better.

Thanks for the info. My main question would be whether or not the new cam would be any better than the old one- I'd much rather pay $3800 (or whatever) than basically probably double that for a new motor.

 

[EdGs]

Any chance of this being a broken valve spring?

 

[Greg8444]

Any chance of this being a broken valve spring?

I am not sure. I'll definitely have a better idea after I get it to the shop, though.

 

[EdGs]

A broken valve spring, you should be able to see without alot of effort, just removing the valve cover.

If it were me, I would like to rule it out just to be on the safe side.

Wishing you the best possible outcome.

 

[Burla]

Thanks for the info. My main question would be whether or not the new cam would be any better than the old one- I'd much rather pay $3800 (or whatever) than basically probably double that for a new motor.

not likely, it isnt a cam issue, we have paper on it- metallurgy tested worn cam, the metal is fine. It is a lubrication issue, my guess is both additive issue and flow issue combined. The issue will follow with the new engine as well, they use cores from old hemi's. Crates wont help either, those are the engines that are currently failing on the board. Two things will help, develop a lubrication strategy we have on the board, search hemi tick, or be part of the larger group that for whatever reason don't have this issue. Nobody knows how many cams are gonna fail, but unprofessional guess would be about 10%. I would consider warranty when deciding because of this issue.

 

[Greg8444]

A broken valve spring, you should be able to see without alot of effort, just removing the valve cover.

If it were me, I would like to rule it out just to be on the safe side.

Wishing you the best possible outcome.

Thank you