Cyl 3 misfire

[Hemimama]

I need some help. My 2012 5.7 had an engine light that showed cyl 3 misfire. Truck has almost 110 K miles and at 100k I changed the spark plugs.
So I change the coil pack and everything is good for about a week. Truck still feels a lil weird but engine light is gone.
Welp.... light comes back on and she starts shuddering real bad. The auto shop is wanting to charge me about $300 just to take the valve covers off and diagnose.


Any one been through this before or have any idea what it could be?

 

[Tim Garceau]

Multiply that $300 diagnostic by about 15 for your final tab.

My condolences

 

[MADDOG]

Is it the same code as before?

If so did you also change the wire lead?

Check the plug to see if it's been firing properly.

 

[Loudram]

I've been through that. If it's not the plug or coil pack which is wasn't on my '14, it could be the lifters. If that's the case then you're talking thousands of dollars for a shop to do it. I don't know what it costs for you to do it yourself, others might know. I traded the truck in while it still ran half decent.

 

[tron67j]

Closest I have come is an old Impala, similar feel. Mechanic/friend changed plugs, still had problem. Changed wires, still same. Switched two plugs, problem moved to different cylinder. New plug was bad. Could also try to switch out the wire with a new one from a new set. If doesn't fix but you plan to keep truck and fix, you'll use them anyway. Good luck.

 

[rickjkline]

It’s a common issue with the Hemi, usually the lifters wear out and they will not open the valves causing a rough running engine. Unfortunately if this is the case it’s a total rebuild at this point. The metal from the lifter wear runs through the engine and it’s over.

 

[scott lass 18]

I need some help. My 2012 5.7 had an engine light that showed cyl 3 misfire. Truck has almost 110 K miles and at 100k I changed the spark plugs.
So I change the coil pack and everything is good for about a week. Truck still feels a lil weird but engine light is gone.
Welp.... light comes back on and she starts shuddering real bad. The auto shop is wanting to charge me about $300 just to take the valve covers off and diagnose.


Any one been through this before or have any idea what it could be?

mine was number one sp301 put new plug in it popped code did coil it popped code ! I have drivetrain warrinty lucky turn out a fuel injector was bad and exhaust pipe replace ok now wish u best of luck my ticking went away but I did fuel injector cleaner befor going to shop ! and code was gone for a week poped back on sadly something to try ? useing Lucas fuel cleaner now in gas !

 

[burner71]

I’m betting it’s a wiped cam.
Does the code come under acceleration?