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2005 Magnum 5.7 multiple cylinder misfire ?

Posted By: 6PacCuda

2005 Magnum 5.7 multiple cylinder misfire ? - 03/03/15 05:16 PM

I have an 05 5.7 Magnum and its getting multiple cylinder misfire code along with like 4 other cylinder codes. It has had plugs, wires and coil packs with in the last year and a half. Could it be the computer. I have heard bad things about these computers.
Posted By: 71yelladustr

Re: 2005 Magnum 5.7 multiple cylinder misfire ? - 03/03/15 09:23 PM

Most common issue is a broken valve spring.
Posted By: 6PacCuda

Re: 2005 Magnum 5.7 multiple cylinder misfire ? - 03/04/15 03:22 AM

So far no broken valve springs. Burnt coils again.
Posted By: Cudajon

Re: 2005 Magnum 5.7 multiple cylinder misfire ? - 03/04/15 04:41 PM

Is the car as delivered or have you added any electronics? Boom box, speakers, amp, etc? Your PCM is a computer with several high capacity transistors driving the coils. Sometimes adding electronics to a car can create a ground plane fault that will not allow the coil drivers to go to zero. There's a lot more to it but the bottom line is it can create a lot of heat in the coils/wiring. A fresh coil can tolerate this for a while but the heat will get it sooner or later. It's why there's a warning about adding stuff to the electrical system of new cars. Good luck.
Posted By: 6PacCuda

Re: 2005 Magnum 5.7 multiple cylinder misfire ? - 03/04/15 04:52 PM

Factory everything on the inside. Only changes to it are fresh air and muffler delete.
Posted By: Cudajon

Re: 2005 Magnum 5.7 multiple cylinder misfire ? - 03/05/15 02:13 AM

Find someone with a diagnostic oscilloscope, I prefer a Pico. Take a look at whayts happening. A bad PCM will be readily evident. Save some money. Replacing parts to find a problem can really cost you.
Posted By: pro451bee

Re: 2005 Magnum 5.7 multiple cylinder misfire ? - 03/05/15 05:24 AM

Multiple misfire codes can go with a bad fuel pump , or in a charger you have a transfer pump too.Connect a fuel pressure gauge to it and drive around.
Posted By: MoparJ

Re: 2005 Magnum 5.7 multiple cylinder misfire ? - 03/07/15 12:54 AM

Quote:

Most common issue is a broken valve spring.




The grand majority of valve spring issues are found on 03-early 04 truck motors.

Although likely an electrical/cpu issue, some of the 05-06 motors have had issues with failing (sometimes falling) valve seats.
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