6.4 engine problems

I have a 2016 2500 6.4 hemi with 42000 miles on it at the dealership with what they are saying major problems . They are telling me it has to be torn down or engine swapped , there is a high misfire count in cylinders 2 and 6 most likely caused by piston slap . When It first started the truck would drop down and stick in 4th gear , using the tow haul would over ride the problem and truck worked fine , I took the truck into a garage and they diagnosed multi cylinder misfire and a bad under shift solenoid but again tow haul seemed to work , unfortunately I kept using the truck thinking it was the solenoid and after awhile it started dropping back into 4th gear again even with the tow haul on so that is when I took it into the dealer . They claimed no problem with solenoids much serious problem . Engine has to be torn down , oil is down to add mark .
Has anyone had these issues ? Can you give me some advice on what should be done ?
on a side note , the truck was getting way better fuel mileage when the tow haul was used right up to when I took it to the dealer .
Any advice would be greatly appreciated !!!

My 2014 6.4L HEMI had piston slap from almost the day I bought it. I took it in to the dealer for diagnosis and they performed a series of tests as recommended from RAM.

There was a TSB for a narrow range of engine serial numbers (2014 production) that had been assembled with undersized wrist pins hence the piston slap issues.

My engine was replaced at around 1800 miles.

If yours has piston slap, then a tear down and repair is indicated.

@MADDOG - do you remember when they got the fix into production?

I can only assume it was before the TSB was issued.

The serial number and production date range identified in the TSB was very narrow applying to 2014 model year trucks with the 6.4L HEMI.

Based on that they must have identified the date of supplier delivery of the out of spec wrist pins and how many were delivered.

The engine exhibited quite a bit of what I thought was lifter noise when I bought it. After it warmed up it was no noisier than other HEMI powered trucks. That may have scared off some other buyers. It wasn't long after I bought it that the noise got louder and didn't cease once warm.

The truck was produced in June of 2014, I purchased it in March of 2015 and the engine was replaced in April of 2015.

I too had one of the 6.4 engines with the bad wrist pins. Sounded like a old school diesel. Ram put a new crate engine in it at 5k, running great at 114k. There are only a limited number of these engines they screwed up. If you're the original owner the dealer should be getting you hooked up with a new engine. My concern is if yours lasted this long to begin with, it probably wasn't one of the affected ones. Which means it is on your tab. Unfortunately with the price of new trucks, when that day comes, I'm just going to replace the parts. New seat cushions and your good to go for another ten years for a wheelbarrow full of money less than new.

OP's truck is 2016 and I really doubt is part of the wristpin thing. As stated, that was a really narrow range and should have been solved well before any 2016 model trucks were built.

The 4th gear thing is a tranny problem (limp mode). I suppose something engine related could be causing it but that seems unlikely. It sounds like you might have two things going on but most of the problems described sound tranny related.

Are you still under warranty or do you have an extended? If so, I'd let them whack away at it until they figure it out. If you're paying I'd get a second opinion before spending a lot of money. I was one of the first 6.4 Hemi owners on here back in 2014 and follow this board pretty close. Engine problems are generally rare (except for a few isolated things like the wristpins). Tranny problems are constant (I'm on my 3rd at 115K).

What @mtofell said about your tranny is so true. I have never had any issue with my 6.4 Hemi, it is so awesome. I do know that if the improper oil and/or lots of idling will cause issues with the Hemi .. or any Hemi with MDS.