Well i'm pretty new to this and i'm trying to find the best avenue to take. i have a 2012 Ram 1500 5.7 Hemi and about two weeks ago or so i started feeling like the truck starting to lose power. so i figure a good oil change and a set of new plugs and some 93 octane fuel would give it a good boost. well not the case. i changed the plugs and started shooting a code. i've never had it shoot a code before. i throw it on the code reader and P0305 is what i got, Cylinder 5 misfire. so i change the coil pack and still the same. so i alternate coil packs to see if i get it to chase. continue to misfire on cylinder 5. so now i'm at a loss and not sure what's next as i cant figure out what is causing the misfire. can anyone help me out?

 

Moving this to 4th Gen Ram section for ya. Welcome to DF!

 

Thank you

 

Pull the spark plug and visually inspect it. If you don't notice any cracks of the insulator or other obvious damage, swap it with another cylinder. It's possible either the spark plug is bad or it was damaged during the installation process.

-Rod

 

Well actually I changed the spark plugs twice. I was sold the iridium to begin with and didn’t realize that I needed the copper resistor so I put the right spark plugs in and still have had misfire with two different sets of spark plugs so I don’t think it’s the spark plugs. After doing more research and talking with others, it may either be a broken valve spring or a bad lifter and cam shaft. I’m hoping it is the valve spring over the cam shaft. Either way I’m expecting his to be very expensive

 

But the cylinder #5 misfire didn't start until after you changed the spark plugs the first time (due to the perceived loss of power)? Granted it could just be a coincidence that that is the time some unrelated issue decided to happen, but that seems unlikely.

Also, I'm about due to change the spark plugs on my 2014 Ram 1500 Hemi and I was planning to put Iridium plugs in it just like I put in my prior 2011 Durango Hemi. May I ask what you learned/experienced that caused you to go back to copper resistor plugs?

-Rod

 

the irridium burns way to hot and could possibly burn a hole in your cylinder wall. The copper resistor doesn’t burn as hot and is what originally comes in the motor. That’s how it was explained to me

 

Thank you for the information. I guess that's one less thing I can spend too much money on.

-Rod