2017 6.4 Low Power ?

[jethro998]

Hello,

I am new to this forum and semi-new to the Hemi 6.4 (owned a 2014 6.4 2500 for a brief period). My truck now, is a 2017 RAM 2500 CC LB 4x4 with the 6.4 Hemi and 3.73 gears. I bought this truck with 45k miles, it now has 55k miles. I tow a 2,700 lb 8x16 enclosed trailer with about 1,000 lbs of cargo. At 3,000 feet above sea level the truck is running in 3rd gear at 70 mph on the flat, it will run in 4th sometimes. No check engine lights. Truck engine feels like its running smooth and trans shifts smooth as well. I just moved 500 miles and used said trailer. I know this is a gas truck and it doesn't have loads of power, BUT, I am thinking there is possibly something wrong. Another scenario, pulling a hill with said trailer (3700 lbs) on a 5% grade at 5,000 ft above sea level, truck shifts into 2nd gear at ~65 mph and still cant hold speed. Is this normal? I had a tailwind wind pushing most of the way and still managed to get 5.5 mpg ( I cant imagine if a head a headwind, LOL). Empty I get around 11 MPG. Max towing is 12,500 and I feel strongly that if I had a even an 8,000 lb trailer, it would not pull it. Note, when I floor it (no trailer or load) it won't break the tires loose (not sure if this means anything, but I was thinking this truck should have much more power). Even empty, on the flat it runs in 4-5th gear, 6th gear seems to be used 5% of the time and that's mostly down hill. We did have a 2014 6.4 and that had the same gear ratio with much more power and much better fuel mileage- up to 16 MPG, empty, and ECO ran much more often, we pulled our 12,500 lb horse trailer and it worked pretty well. Just curious if anything jumps out at anyone here.

Thanks,
Jeff

 

[MoPowered]

You should look at TFL truck on YouTube the tested an 18 or 19 on the Ike Gauntlet and they were kinda experiencing the same thing, Ike thinking it’s all in the computer. The delay between pedal input, transmission shifts and grade changes I think would do it. When I first experienced the computer controlled vehicles back 20 years ago or so it was in our then new 1998 Durango after driving My 86’ Ramcharger it was something that drove me nuts. On my home from work I had one spot where I had to come to stop and I as I proceeded through the intersection the opposite side of the intersection rose and then sharply followed by an incline. The tranny had fits, it started off in 1st shifted to second easily enough right at the point of the first rise, sense the change with the dip, drop in first as I hit the incline and freak the hell out and jump all the way into 5th drive gear and bog up the hill and it did it every time. I thought it was the tranny slipping and even to it to the Dealer several times. I finally had a tech that lived close to me ride with me and had him experience it Andy he was at a loss also. Low and behold it was chalked up to the pcm. Anyway I did the old cable pull reset and first thing I did while it was realer I got was took it to that friggin hill and Viola’ it ran great after that. So maybe try pulling your terminal and see if you can have it relearn and if not maybe look into a clogged cat. A 6.4 with 3:73’s should not have any issues with power. As a side, what size tires are you running?

 

[csuder99]

Empty the truck should easily run in 6th gear so that certainly doesn't sound right. My truck is an older 2500 with the 5.7, same gearing but shorter bed. No problem running in top gear doing 65-70.

My camper trailer is about the same size, 21 ft overall, 8 ft wide and close to 11 ft tall. It weighs ~6300 lbs. On a recent trip to CO the truck did climb two passes in 2nd gear, however that was at higher elevation (10k+ passes) and steeper (up to 9%). Closer to home I frequently tow from 3500 ft to 5-6k ft and it climbs at the "prevailing speed"

Unless you run larger tires something ain't right.

 

[jethro998]

Thanks for the feedback! I am running larger than stock tire, its a 275/65/20 which converts to a 34.1x11x20 (factory wheel) tire, so not much bigger in my opinion than stock (Stock is 33.5). I was curious about the learning of the transit and I am thinking I may start there, after watching the suggested Youtube video.

Does the lack of ECO indicator light coming on tell me anything? Like I mentioned earlier, it comes on ONLY when I am off the throttle, coasting, at ~25 MPH and it comes on for 2-3 seconds. Again, when we had the 2014 2500 with the 6.4, the ECO indicator would be on a fair amount and you could hear it in the engine; I'm not getting that with this truck.

When I called the RAM dealer, they told me that if there are no check engine lights on, then there are no issues. That leads me to believe I will have to figure this out on my own which will be via these forums, or a good local tech.
It is frustrating, I really like the truck other than the lack of power. I haul 2 sleds on my sled deck above the bed, 1500 lbs and it is a dog with those on. Hopefully I can get is solved.

Thanks again!

 

[Steve Tokash]

I dont have much to offer in advice but i pull a 4k lb dump trailer empty and i hardly know its there with my 2014 6.4. Although i am not going up any steep grades or anything but still. Not sure it would make a world of difference but maybe look into a tuner could free up your throttle a little and maybe help with your shift points. I have a diablo on mine with just the stock tunes and the throttle response jacked up and it helped overall drivability when not towing. I dont know if your year has a throttle lag but it was driving me nuts just driving around town i had to do something about that. Good Luck

 

[jaflowers]

Something isn't right. I ran from middle N.C. all the way to Colorado Springs pulling a loaded up UHaul 6x12 (7500-8500 pounds) with around 1200 pounds in the bed of the truck too. Over the Appalacian mountains with ease in 4th gear to middle Tn. I was getting 12.5MPG. From middle Tn to St. Louis my mpg was the same. From St. Louis to Colorado had lots of wind and bad driving conditions, snow and sleet, and was running 9.5-10.5MPG. 2015 6.4, CC, SB, 4x4, 3.73 and stock tires (for that trip). I drive fast, even with trailer, and was averaging 70mph for the whole trip.
Living in Colorado I go up into the mountain frequently enough in the truck, usually fairly unloaded. Up the passes I go into 3rd gear to maintain 65-75mph but that's usually at 9,000 feet or more so lots of horsepower loss from the altitude. Back at my families in Tn the trucks power feels great even with the 3.73, only at 1000 feet there.

 

[jethro998]

Thanks again for the input. I am thinking the tuner would be great, but I believe there is an underlying issue. In town, it is really slow to accelerate in 2nd gear with just my sleds on, again 1500 lbs or so. On the interstate, when I floor it, it will run in 2nd gear up to about 65-70 then shift to 3rd and will stay in 3rd maybe 4th on the flats, with my 1500 lb payload. Could it be the CAT or another emissions issue that isn't causing the check engine light to come on? I dont want to dump $1500 into a CAT + labor if that couldn't possibly be it.

I should note again, I am getting 5._ MPG with a tailwind and a 3500 lb trailer driving from Missoula MT to Western Wyoming, 5% grade at most. Getting 10._ MPG empty highway driving.

I dont believe the previous owner towed anything as the factory paint was in the hitch receiver as well as in the factory 5th wheel (no salt on the roads out here either). If the previous owner always "idled along" could it be that the exhaust or other emissions is really loaded up with crap, at 55k miles on the truck?

Air filter looks clean, I am going to replace that just because.


Thanks everyone

 

[2003F350]

You shouldn't be in 2nd gear at 65-70 mph no matter what you're pulling. I'm not even sure mine will stay in 2nd gear that long. The lowest my truck has ever run at 65-70 was 3rd gear, and even then it only barely shifted into it.

You've got something serious going on, I'd consider stopping by your local autoparts store to see if they can check for codes (CEL could be burnt out or disabled). If there are some, get it in to a service center. If there aren't, try as said above, unhook the battery for a while (it'll clear stuff out) and then drive it some more to attempt a re-learn.

 

[62Blazer]

You should look at TFL truck on YouTube the tested an 18 or 19 on the Ike Gauntlet and they were kinda experiencing the same thing, Ike thinking it’s all in the computer.

Not even close to what TFL stated and way different scenario as compared to the OP. They were pulling something around a 12,000-14,000 pound trailer up a 7% grade at over 10,000 feet elevation.......way more extreme situation.

To the OP, what you describe does not sound right. I just got back from a 9 hour round trip through the hills of Tennessee pulling around a 4,000 lb. trailer in my '16. It does have 4.10 gears but that is countered by the 35" tires. Never any issue maintaining 75 mph and never went below 4th gear and averaged 8-9 MPG.

 

[jaflowers]

To the OP, what you describe does not sound right. I just got back from a 9 hour round trip through the hills of Tennessee pulling around a 4,000 lb. trailer in my '16. It does have 4.10 gears but that is countered by the 35" tires. Never any issue maintaining 75 mph and never went below 4th gear and averaged 8-9 MPG.

My thoughts and experience exactly.

 

[Daw14]

I would check the catalytic converters maybe one or both are clogged.

 

[John Sabatula]

It's just set up wrong from the factory, my 18 6.4 6 speed is a dog to. My dad's 5.7 with 8 speed will run circles around my truck. Matter of fact my 12 5.7 6 speed is a dog too. Prolly how they geared the tranny and shift points in em. Wish I'd got the 8 speed in mine.

 

[LeesEvoX]

It's just set up wrong from the factory, my 18 6.4 6 speed is a dog to. My dad's 5.7 with 8 speed will run circles around my truck. Matter of fact my 12 5.7 6 speed is a dog too. Prolly how they geared the tranny and shift points in em. Wish I'd got the 8 speed in mine.

I had a 12 with 5.7 hemi, 6 speed. And 3.55 gears.

Stepped up to a 2020 2500 with 6.4 hemi, 8 speed, and 4.10 gears.

Oh.. my... god... what a difference. In fact, the only time I realize I'm in a 3/4 ton truck is when I have to hit the brakes! Lol.

This thing moves out, and has been tested to just edge out the 1500 on the freeway.

Sent from my SM-G950U using Tapatalk

 

[2003F350]

I had a 12 with 5.7 hemi, 6 speed. And 3.55 gears.

Stepped up to a 2020 2500 with 6.4 hemi, 8 speed, and 4.10 gears.

Oh.. my... god... what a difference. In fact, the only time I realize I'm in a 3/4 ton truck is when I have to hit the brakes! Lol.

This thing moves out, and has been tested to just edge out the 1500 on the freeway.

Sent from my SM-G950U using Tapatalk

My PW has the 6.4, 6 spd, and 4.10s. I have no issues making anything move. Payload could be better but hey, tradeoffs have to be made for the flex.

But I'll say this - I can smoke the tires into second gear from a dead stop.

 

[Firebird]

It's just set up wrong from the factory, my 18 6.4 6 speed is a dog to. My dad's 5.7 with 8 speed will run circles around my truck. Matter of fact my 12 5.7 6 speed is a dog too. Prolly how they geared the tranny and shift points in em. Wish I'd got the 8 speed in mine.

I hated the power delivery of my 6 speed 2018 compared to my 8 speed 2019, the ZF is a game changer!

 

[Toddz]

I would take it to the dealer and have them drive it. It sounds like a possible transmission issue to where the shift points are not right. I have been at 65 in second gear, but that was with a 9,000 lb travel trailer in tow up a 7% grade and not coming close to slowing down (the 3.73 gears are way too tall so to keep rpms up around 4000 rpms it performed best in 2nd on really long/steep grades).

 

[MoPowered]

Just my 2 cents worth. I pulled a 10,000 construction trailer for a friend who’s truck broke down. Being it’s a Power Wagon with the 5.7, 4:56’s and 37’s the only thing that I noticed was the tires definitely weren’t made to tow, lol.

 

[jethro998]

Thanks everyone. I am going to get it dyno'd on Wednesday and to the mechanic on Thursday. Will see what happens.

Jeff

 

[GsRAM]

Good luck man. As said something definitely wrong with your truck. My 17, 6.4, 3.73 truck pulls my 6k tt like a freight train, even in the mountains.

Unloaded it's a heck of a lot faster than a 7k HD truck has any right to be.

Hope they can get yours sorted out so you can enjoy the truck. Yes even with the 6 speed!

 

[thkbaron]

I don't have a ton of experience but my truck will pull easily in 4th gear all day long and rarely downshift again unless it's a really steep grade. 5th and 6th gear are overdrive gears so it's tough to pull a load in those although 5th isn't too bad depending on the load.