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.