3.5 Running VERY Rough, Black Spark Plugs

[carspaz]

Alright, it's a long story, so I'll try to make it brief. Stock 3.5, no upgrades, 87 octane.
The car runs rough 99% of the time. Not rough as in a lopey cam, more like it's running on 5 (or 4) cylinders. Had been getting a 0304 (cylinder 4 misfire) code at this point. Ran Seafoam through it a few different times a few weeks apart.....seemed to help the idle for a few days, but then back to normal.
Took it into my Chrysler dealer, said it was a bad coil pack on cyl 4. Replaced it.
Few days later, the problem shows back up. Took it in and the dealer said the same coil pack crapped out, replaced it again...for free.
Few days later and the same problem, but it's starting to get worse. Took it to an independent shop. They looked it over, said they thought it was either a bad EGR, EGR needs flashing, or PCM needs flashing. They can't do it since Chrylser doesn't give them the updates to do this work until 4-5 years after the vehicle production (supposedly).
So I take it BACK to my dealership. First they tell me it needs new plugs (57,000 miles right now). They wanted to charge $180 for the plugs and install. I tell them I will do it, just put the intake back on.
I stop by later that evening to pick it up, but the mechanic and the guy at the service counter were both gone for the day. The notes on my invoice said to run some engine/fuel injector cleaner through to see if it helps. If not, it probably needs a fuel injector on the cylinder. Well, I've ran the engine cleaner through twice already, not doing it again. So the vehicle limps home. Somewhere in here, the 0300 (multiple cylinder misfire)code pops up. I throw new plugs in it a few days later.
It's been around a week and MAYBE 100 miles since I changed the plugs, and the engine runs just the same, if not a little worse, than it did before. I pulled the plugs out again today, and they are all pretty black and sooty. Still have the 0300 code. First 3 pictures are drivers' side bank, forward most, middle, and rear most (I think cyl 2,4,6). 3 pictures in next post will be passender side bank, forward most, middle, and rear most.
Anyways, I'm about at my wits end with this engine. Could a bad EGR valve cause all this chaos? What about a bad injector? Am I wasting my time/money installing just ONE injector?
Sorry for the long rant, but any help that anyone can provide would be greatly appreciated.
Thanks in advance,
Jared

[carspaz]

Passenger side
Front, middle, and rear plugs.

[X's Revenge]

sma ething my 09' did, have them check a TSB for a "Crankshaft Positioning Sensor Shim", that seemed to fix alot of 3.5 challengers running the similar case, unfortunately it didn't help mine, but it may be an avenue to check out.

[1fastsedan]

What plugs are those? The electrode looks HUGE.

You may also want to look into this one: http://www.wkjeeps.com/misc/LX/TSB/TSB_0900505.pdf

[carspaz]

The plugs are Bosch Platinum Plus.
I was leaning in the direction of the whole decarbonization thing when all of this first started. Not really sure why I got talked out of it.....I know the Chrysler mechanic was pretty positive that wasn't the issue. Would that foul my plugs out so quick?

[rwalshphoto]

Personally, I wouldve replaced them with the factory plugs just so you arent introducing any more variables. It sounds like PCM issues to me - a bad EGR I could see causing some rough idle but not to the point where you'd have to limp it home.

[carspaz]

Well, I guess "limp" was a bit of an exaggeration. It doesn't enter limp mode, but it just runs like crap. The miss is definitely a LOT more noticeable when you're at a red light. You're literally bouncing in your seat. Once you're over 15-20 MPH, it's a lot less noticeable, but you can still feel the miss. Also, sometimes the transmission doesn't want to shift through the gears like it should. It will get up to right around 5,000 RPMs before it shifts into 2nd. This doesn't happen everytime though, but it started the same time as the misfire issues.

[TanT]

You're number 4 plug looks horrible. All others look normal.


Swap that injector with another one and see if the problem swaps with it, if it does, you know you have a bad injector. Replace injector.

[Bryali]

Wow, based on the pictures it seems to be the driver's side middle cylinder, #3. From my memory, the cylinders are 1,3,5 on the driver's side and 2,4,6 on the passenger's side. That's how it is on Chevy's anyway so I'd assume domestics are all numbered the same. I could be wrong, it's happened before. It does seem to be specific to that cylinder, though. Good luck with it!

[fnkychkn]

please update your vehicle profile in User CP. thank you.

[Mics Mag]

That middle cylinder on the drivers side is burning with too much fuel and not enough air. To a smaller degree the last one on the passenger side. It could be valve related (cam,lifter) if the fuel injector swap doesn't change the location of the trouble. But id love to hear from the experts on this one, like the funky Chicken.

[fnkychkn]

still waiting to find out what you're driving.

[carspaz]

Hey fnky, User CP has been updated. Just to make sure we're all on the same page, it's an '05 Dodge Magnum AWD with 3.5L HO. Completely stock. No power adders. 87 octane.

I'm popping a new injector in that cylinder today. Will keep everyone updated. In the meantime, suggestions are still welcomed with open arms.
Thanks again everyone for the ideas so far.
Jared

[fnkychkn]

possible candidate for TSB 09-010-06.

also found this in online database:

Case Number: K20134718
Vehicle Issue: P0304 : 6E : CYLINDER #4 MISFIRE:Valve springs.
Year: 2005
Model: LX - 300
Category: DTC / Error Message
Symptom: Engine Misfire
Scan Tool Diagnostic Trouble Codes / Error Message: P0304 $6E Cylinder #4 Mis-Fire
Condition Verification: Yes - Intermittent | Yes - Continuously
Case Verification: Using a spark tester verify that each spark plug receives adequate spark. If not check the following. If the spark is weak or missing for one or more of the cylinders on a DIS (direct ignition system) or COP (coil on plug) system, be sure to verify that: the cam timing is correct, the timing chain is not excessively worn or stretched. Check for broken or sheared keys or dowel pins in either the cam sensor or crank sensor sprockets. Check secondary ignition, cap, rotor, wires, (if equipped) Check primary ignition: with lab scope and or PEP module function of the DRBIII. Using an accurate fuel pressure gauge check fuel system pressure, compare fuel pressure to specifications in service manual. Check fuel volume at fuel rail it should pump at least a pint in 20 sec. Check for fuel pressure bleed down compare to specifications in service manual. Check fuel quality, check for alcohol % in fuel: A quick test for alcohol is to place an inch or so of water in a clear container and mark the water levels. Fill the container to the top with fuel from the vehicle, cap the container and mix the contents. Let the mixture settle and look for the water level to rise. The increase in the water level indicates the amount of alcohol in the fuel. Check for injector's firing, if the injectors clicks when actuated they will need to be checked for lack of fuel flow: A quick test is to actuate the fuel pump with a fuel pressure gauge at the fuel rail, turn pump off, actuate the an injector three times and note fuel pressure drop on gauge. If no drop in fuel pressure injector is plugged. Adding propane at idle to the purge vacuum port and observing O2 sensor readings is also a good indicator of poor fuel delivery . Check leak down and compression if no problem found see recommendation below.
Recommendation: Remove valve covers and inspect the valve springs. Replace damaged valve springs as needed.

[carspaz]

Wow.....Information overload. Thanks fnky!