Brand new member!
I purchased a 2006 R/T with 112000 miles. First off, the Magnum runs fantastic once it starts. No issues of any kind that I can find.


Here's the needle in a hay stack - meaning this is a sporadic issue, not constant.


I am experiencing a crank-no-start issue with odd symptoms. I turn the key 2 clicks to allow the pump to prime. I turn the key and the engine starts to crank. I will get 1 or 2 revolutions and then I get an interrupt in the crank. All of my dash lights stay on. The only thing that stops is the cranking. Then it starts cranking again. Sometimes the engine immediately fires after that delay, sometimes it needs to crank 3-5 times. I could then shut the car off, turn the key and fire up immediately. Here's the really weird thing about all of this - when I experience the stutter in the crank my PCM resets. Therefore my emissions cycle never completes and now I can't get my car e-checked.


My first inclination is battery. I'm in Ohio and this problem has become daily in these negative temps we are having. This feels temperature related but not necessarily engine temp related. I have had this stutter/PCM reset after having the car off for minutes. I measured my battery and she has a solid 12.6+. I measured while cranking (but couldn't replicate the stutter) and volts jump up when she's running. I don't think it's necessarily a voltage issue but I don't know much about cold crank amperage, etc.


The car has a new starter. I'm not throwing any codes either. I swapped out the starter relay but no change.


I'm looking to see if anyone out there has either had this experience or might suggest some places to look. The only way I know of for the PMC to reset is by sending a code or disconnecting the battery. This being the case I have to believe I'm somehow losing power to the PCM. I suspect that this interruption in power to the PCM results in a no-start.


Taking to the shop this week but want to see if anyone can beat them to the punch!


Thanks.

 

My problem has been resolved with the assistance of a Chrysler Master Tech out of Detroit.


I took the Magnum to a shop in my area (RadAir Wickliffe, OH). They checked all the logical electrical things like battery, loose cables, grounds. They escalated to Chrysler direct and described my symptoms. The answer that came back was a little surprising.


First, they asked about the spark plugs. The plugs that the previous owner installed were the Champion Platinum plugs (there's a lot of debate on the forums about platinum on the 5.7). They were the right part number but the tech asked where the plugs came from. Based on the history that the previous owner supplied me we speculated they came from an Advance Auto or other discounter.


The Master Tech advised us to remove those plugs and replace them with plugs from a Chrysler dealer - stating that the plugs the dealer gets are different than the plugs the box stores receive - even though same part number.


We replaced the plugs with the OEM (copper) from a dealer. This resolved my problems and the 5.7 runs better than ever. Zero mis-starts and the PCM no longer resets.


I question the recommendation about getting the plugs from a dealer but at this point I don't question the results. For all I know I could have had bad plugs and resolved my issue with plugs from Advance Auto. Don't care at this point!!


The explanation given was that they have seen this problem on other 5.7s and that using the platinum Champion plugs somehow causes an arc on some vehicles that goes back to the PCM and causes a reset. This arc and corresponding PCM reset causes the ignition sequence to interrupt.


Let the opinions fly!