Performance at higher altitude

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

OLEJOE

Senior Member
Joined
Sep 23, 2019
Posts
231
Reaction score
153
Location
N. La
Ram Year
2022
Engine
6.7 CTD
I have a 2018 CTD that performs and runs great. But if I get above 5k ft ASL it acts crazy. Running with cruise on, it will start to pull (towing) and then kind of hang up until the speed drops then downshift and take off. The transmission and exhaust brake act screwy as well. My question is: has anyone else had or heard of this happening and what the cure might be? Just returned from a trip Albuquerque where it was 6-7k ASL and truck surges and acts so crazy then I got back to lower elevation and it runs perfect. ???
 

mtnrider

Senior Member
Joined
Sep 25, 2014
Posts
3,164
Reaction score
3,407
Location
Georgia
Ram Year
2016
Engine
6.7 Cummins
Lived in Colorado above 7000 ft for many years and never had an issue with any of my Cummins trucks. How much weight are you pulling and are you locking out 6th gear? I rarely run cruise control (especially when towing) unless it's completely flat stretch of road.

Is the truck still under warranty? If so take it in

.
 
OP
OP
OLEJOE

OLEJOE

Senior Member
Joined
Sep 23, 2019
Posts
231
Reaction score
153
Location
N. La
Ram Year
2022
Engine
6.7 CTD
Towing 7k TT and it will do the same on cruise in 5th plus the fuel pedal gets really touchy in 5th. It is still under warranty but they look at me like I’m crazy when I describe what it does. We’re at less than 200 ft ASL so it isn’t going to do all the crazy stuff. Just wondered if anyone else had the same problem. Get below 5k ft and it does awesomely.
 

Bob Macknight

Senior Member
Military
Joined
Feb 3, 2019
Posts
185
Reaction score
166
Location
surprise az
Ram Year
2015
Engine
6.4hemi
check your tranny fluid level,and look to see if the tranny dumped any fluid out of the vent tube,had that happen years back traveling cross country tranyy acted up and let some fluid out the vet tube on top of tranny,i was told the change in altitude and the fluid heating up causes the fluid to expand thus the dump of fluid.
 

jejb

Military
Joined
Apr 7, 2020
Posts
1,569
Reaction score
1,439
Location
NW Arkansas
Ram Year
2022
Engine
6.7 Cummins
I've towed an 8k trailer over Monarch Pass (11k) and other passes in CO. No issues at all with my 18 CTD Ram, whether using CC or not. There must be some kind of altitude sensor in the system. I think I'd start looking there.
 

mtnrider

Senior Member
Joined
Sep 25, 2014
Posts
3,164
Reaction score
3,407
Location
Georgia
Ram Year
2016
Engine
6.7 Cummins

Tumbleweed

Senior Member
Joined
Dec 10, 2018
Posts
286
Reaction score
384
Location
Michigan
Ram Year
2018
Engine
6.4 Hemi
Perhaps take it in to a dealer at those elevations? They should know more & have the experience.
 
OP
OP
OLEJOE

OLEJOE

Senior Member
Joined
Sep 23, 2019
Posts
231
Reaction score
153
Location
N. La
Ram Year
2022
Engine
6.7 CTD
I just wonder which sensor detects altitude ? I found a guy on another forum who has had the same problems with his DRW 3500 and hasn’t gotten it figured out. Maybe I can find a dealer service person who will listen to what I’m trying to tell him or her what it does when I get to higher elevations. It’s like you flip a switch. Was coming down a grade of approximately 10k feet and the exhaust brake wouldn’t work, the transmission would just shift to a lower gear when I let off on it. Got to the bottom at around 6,700 and exhaust brake started working again. I’ve been to the dealer and tried to explain what it was doing she evidently didn’t explain it to the technician and I got the all good answer. ???
 

Dennis Shellito

Senior Member
Joined
Dec 17, 2018
Posts
198
Reaction score
86
Location
Ft. Morgan, CO
Ram Year
2011
Engine
Cummins IBS
Perhaps take it in to a dealer at those elevations? They should know more & have the experience.


That sounds like the best advise, and they will be able to diagnose a problem that the lower elevation techs will blow you off as crazy and imagining things. My 2011 runs just as good up mountains as it does on flat ground at SL, which is fantastic.
 

mtnrider

Senior Member
Joined
Sep 25, 2014
Posts
3,164
Reaction score
3,407
Location
Georgia
Ram Year
2016
Engine
6.7 Cummins
I just wonder which sensor detects altitude ? I found a guy on another forum who has had the same problems with his DRW 3500 and hasn’t gotten it figured out. Maybe I can find a dealer service person who will listen to what I’m trying to tell him or her what it does when I get to higher elevations. It’s like you flip a switch. Was coming down a grade of approximately 10k feet and the exhaust brake wouldn’t work, the transmission would just shift to a lower gear when I let off on it. Got to the bottom at around 6,700 and exhaust brake started working again. I’ve been to the dealer and tried to explain what it was doing she evidently didn’t explain it to the technician and I got the all good answer. ???


MAP sensor reads the barometric pressure.

With that said it doesn't make what you are saying about the exhaust brake and it down shifting when you let off the accelerator? Is that under braking? What gear were you in? How fast? The torque converter has to be locked for the exhaust brake to work. Maybe your actuator is failing? Pretty common issue with these trucks.

I used to live at 7200ft and would drive to my place in summit county every other week which was ~11k ft and never had a performance issue due to/related to altitude.


.
 
OP
OP
OLEJOE

OLEJOE

Senior Member
Joined
Sep 23, 2019
Posts
231
Reaction score
153
Location
N. La
Ram Year
2022
Engine
6.7 CTD
That’s what’s weird about what it’s doing. Once I get back down below 5000 feet, it runs perfectly. Sorry for the late replying but my internet has been down at home and my cell won’t work without wi-fi. Thanks for all the advice. I’ll try to get it looked at next time I get high. Lol
 

jdhreiss

Junior Member
Joined
Oct 27, 2020
Posts
10
Reaction score
5
Location
SW Washington
Ram Year
2013
Engine
Cummins 6.7
Just back from a week long trip through Sawtooth Mountains in Idaho - Towing and empty - I didn't see any issues up to 7,500 ft in my '13 with 87k miles. I think the O2 sensor(s) can tell the A/F ratio and adjust accordingly, but I'm just a shade tree wrench on a forum......
 

Forum statistics

Threads
194,925
Posts
2,864,170
Members
155,295
Latest member
atomota
Top