P0305 Cylinder Misfire, Flashing Engine Light @3k rpm HELP I tried a few things

Hi,

I have a 2010 Ram 1500 with a 5.7L Hemi.

Recently my truck started to flash an engine light under medium (2k-3.5k rpm) acceleration.
The code reader showed an error P0305.

Also hesitant at times during throttle & rpm gauge slight variations (200rpm surge) during normal driving conditions, also it would shake very little once throttle released again and cylinder picked up. Defiantly not good on the engine!

-So I installed new identical part # spark plugs, no difference, still code P0305. Same symptoms.

-Swapped out coil pack with another cylinder, still P0305 flashing during acceleration.

-Removed #5 FUEL INJECTOR, inspected and even swapped out with a different cylinder and still throws a 0305 code, only flashing, no steady engine light.

-I inspected MAP sensor, cleaned the camshaft sensor, and air temperature intake sensor, no change.

Engine has noticeable higher pitch tick at idle aswell which sounds like it's coming from #5 cylinder.

Truck is parked for now, not sure what next? I don't have the tools for a compression test sadly, I will add a picture of spark plugs I replaced.

Remove your valve cover and look at the rocker arms as someone turns it over ,observe the amount of movement , if one isn’t like the rest it is pointing to a lifter/cam issue . May remove fuel pump relay before cranking it.

I think you're right.


I suspected possibly valve spring but everything is tight. Only thing i noticed was that Rocker arm has play left/right and up/down on #5 because ?decompressed? Cyl? I suspect, you can see the play in pictures.

Thinking rocker arms possibly now, as the tick does sound like it is coming from somewhere around there. Can hear it from the top, and under the truck

Rocker arm is off centered on valve stem due to lifter rollers going bad.

Classic signs of lifter failure unfortunately.


Here's my ground off cam lobe and the failed lifter. Had engine rebuilt with new mild cam, non MDS lifters, springs and pushrods then dyno tuned. Pricey but runs better than ever did now.
There is a DIY thread on this forum if you want to tackle the project yourself.

The tick doesn't sound like the bottom end.

I pulled valve cover again to double check if I missed something.
Cyl #5 the rocker arm nearly moves 1/2" on the shaft side to side, so this got me thinking that the push rod ball must be gone on the intake side. Which would cause the issues im having I would think, and also would explain the 'pinging' tick sound that's noticeable, probably the push rod bouncing off of the rocker arm. No?

https://youtu.be/PebKHDFw5R4

Here shows cylinder 5 rocker arm short video

SimonStu said:

Hi,

I have a 2010 Ram 1500 with a 5.7L Hemi.

Recently my truck started to flash an engine light under medium (2k-3.5k rpm) acceleration.
The code reader showed an error P0305.

Also hesitant at times during throttle & rpm gauge slight variations (200rpm surge) during normal driving conditions, also it would shake very little once throttle released again and cylinder picked up. Defiantly not good on the engine!

-So I installed new identical part # spark plugs, no difference, still code P0305. Same symptoms.

-Swapped out coil pack with another cylinder, still P0305 flashing during acceleration.

-Removed #5 FUEL INJECTOR, inspected and even swapped out with a different cylinder and still throws a 0305 code, only flashing, no steady engine light.

-I inspected MAP sensor, cleaned the camshaft sensor, and air temperature intake sensor, no change.

Engine has noticeable higher pitch tick at idle aswell which sounds like it's coming from #5 cylinder.

Truck is parked for now, not sure what next? I don't have the tools for a compression test sadly, I will add a picture of spark plugs I replaced.View attachment 495197

Click to expand...

Well, we now know several things that AREN'T wrong....
As a professional technician/diagnostician, I see this problem almost daily. Sadly, many (the majority) of so-called professional shops load the parts canon too, and, after spending a lot of time and money on new parts, fail to accurately find and fix the problem. e.g. I had a 2001 Jeep Cherokee in a couple of weeks ago with a DTC for cam/crank sensor intermittent signal loss along with all 3 primary coil primary control circuit faults. A prior shop had replaced the crank sensor, coil pack, and spark plugs. The symptom was hot idle instability and surging/dying like a fuel control issue might be the culprit.
I went by the scanner to direct me to the particular place that caused the DTC's. The VERY first thing I checked was his battery. Why? It started the car just fine. The battery was bad with only 30% capacity. I replaced the battery, and the DTC's for the primary ignition coil control circuits cleared right up, and the car ran better, but, alas, the surging/dying persisted, as did the cam/crank DTC! What to do next? Get out my scope and retrieve wave form patterns from the Cam sensor and the crank sensor. I observed a damped wave form across the 5V circuit to the crank sensor, and when this occurred, the wave pattern inverted! The damped wave form screamed ignition feedback to me. Sure enough, the new coil pack was bad (Aftermarket). I pulled it off and checked the new plugs and observed that they were improperly gapped, and corrected that, cleaned them, and installed them back into the engine and replaced the coil pack. (I was forced to use aftermarket, due to FCA having a 1-2 month backorder on said part. I used Standard Motor Products coil pack because I have great success with their product.) I cranked the car up, and it ran better for about a minute, then the same issue. WTF??! So, I replaced the plugs (Champion RC12ECC) and it still had the problem. I took out the new plugs and put an ohm meter across them. Resistance varied from 20K ohms to 200K ohms! Same as the other new ones the prior shop had installed. I ordered NGK's and tested them first and they all averaged 4K ohms! Installed them and the car ran better BUT there's another issue. The cam sensor was 15 degrees behind crank angle! The result was a slight hesitation or bog upon snap throttle in the bay. I adjusted it (it sat on the top of the oil pump drive housing where a distributor would have been on an older rendition of this 4.0L) After properly calibrating cam/crank sensors, the car runs like new!
You are at a major disadvantage without an automotive oscilloscope and many VERY expensive probes and sensors which work with the scope to give you accurate data to lead you to a repair. Scanners were never designed to tell you what particular repair might be necessary, but to lead you to which system to diagnose. Although the DTC flagged the crank sensor on the Cherokee I was repairing, the true culprit was secondary ignition feedback across that circuit, creating a ghost or phantom code.

Does look like the rocker has a fair amount of play in it leaning towards lifter/cam classic signs so far do you have any vids of it running? how many miles on it?

I took valve cover off once more this morning.
The rocker arm is still connected to the push rod and also doesn't appear bent, but alot of play with how the rocker arm moves compare to the other push rods, can't tell if it is still attached to lifter without removing the rocker, but doesn't have much play within the stroke, also hand cranked the engine and the push rod does tighten up then, but I suppose through fast movement it could slide and clunk around.

I took a video of truck running, can't hear tick during startup but as soon engine idles down/or warmed up it starts ticking.

The tick before sounded like it was coming from rocker location, tho in this video it sounds almost dead center of the engine... cam, lifters?

Looks like I'm in for a new engine https://youtu.be/xAaHZfIasI0

How many miles on your truck?

268000kms

I hate to say it but this is exactly what my truck did when my lifter went bad and ate my cam. Except I was on cylinder 3. It’s been 50k miles since I had them all replaced and a new cam and the truck runs great. Just wasn’t cheap

Much appreciate all the replies. I have lifters/ valve/ gaskets on the way, will have to pull the head and see what's happening in there. I think I'll borescope cam for damage before thinking about pulling it. I didn't drive very long with the tick, so hoping cam will still be ok until I can afford a complete top end rebuild.

So today I had some time to pull the head off, there was a problem lifter on cyl 5. Roller won't move, doesn't look too horrible tho, I quit driving the truck once the lifter was stuck basically, as it was running bad.

Not sure, could I just replace the 4 lifters (I have parts on hand already)?
Don't really have the time (got visitors coming) and $$ right now for a full lifter/ cam/ top end rebuild... Found out I will also need to get a new waterpump, little wobbly in the bearing.
Will have to get some extra tools, how many kms/ miles could it last just to throw new lifters in? Pushrods look alright, not bent, have new ones as well.
I will borescope the camshaft tomorrow, see how it looks.

Borescope the cam make sure it looks ok at a minimum do the lifters on that whole side Also replace your exhaust bolts while the head is off.

Once I will turn the engine over by hand tomorrow I'll find out more with the borescope. Hoping to get away atleast a couple months/maybe next year with just a lifter fix.

Had the time to hand crank the engine and take a short video to see the cam rotate, defiantly appears wiped/grooved into on cyl 5.

I added a new lifter to that cylinder and hand cranked the engine several rotations.
The lifter seems to be lifting up fine again, tho not sure how much life I would get out of it, hard to say how wiped the cam is on that video, hopefully will be picking my borescope up later in the day.

https://youtu.be/I9vFSfP3MUc

After looking at that vid you need a new cam its shot no way around it its not going to run good at all. You can do the cam/lifters in the truck its not that bad of a job sounds worse then it is about $800-1k in parts can done in the truck 1-2 days you already got one head off.

Thanks for your input, I ended up pulling the 2nd head just now. Ordered a bunch of parts aswell, they should be 1-2 weeks away:

-camshaft, water pump, all lifters, new pushrods, valve stem seals, headgaskets, new head bolts, intake manifold gaskets, timing cover gasket, oil pickup tube o-ring, a few exhaust valves,
shall I replace all intake/exhaust valves and springs too?