Hello, first time posting on here.
I have a 2014 ram 1500 Big Horn- 5.7

For about a month I’ve had a cylinder 5 misfire
Along with random white smoke from tailpipe.
After bringing it to two shops and these repairs…
plug, coil pack, injector, compression test, leak down test, and a reman pcm.
the white smoke isn’t coolant, it’s excess fuel burning.
With the compression and leak down, the technicians ruled out head gasket & block issues.

anyone have recommendation what to do next?
The truck doesn’t tick except on cold start.
cam? Lifters?
thanks

 

If it were a cam or lifter issue, I would think the compression test would have shown that.... What plugs are in it, and what is called for from the factory?

 

The spark plugs that were in it were NGK iridium IX. I replaced them with the same plug. My thoughts exactly, if good compression than that rules out a lot of options.
My next step was remove valve cover and check solenoids?

 

Is cylinder 5 even involved in the MDS system????

 

Not entirely sure. I think they may be on 1,4, 6, 7. The main reason I’m posting is the dead end I keep running into. Open to suggestions

 

Does it misfire immediately at startup? Or does it have to warm up a bit first?

 

It runs rough while in gear, no idle misfire. Typically going around 1400-1800 rpm is its worst. But after turning it off and letting it sit for 15-20 min. Once I start it again and drive it’s burning excess fuel and smoking for about 5-10 min before going away

 

Try unplugging the front O2 sensor(s?), and go for a drive. Run any better?

 

Since you mentioned plug, coil and injector, all singular, are you sure the correctly identified cylinder 5 and replaced those on the correct cylinder? Did the spark plug from cylinder 5 look different from any others that were presumably removed at the time? Can the shop backprobe the injector and capacitively scope the ignition coil during the misfire condition? The injector backprobe wouldn't be so tough, but capacitively monitoring the secondary of the ignition coil under load without a dyno could be a challenge.

-Rod