Isata 5 30 FW engine performance going uphill

[msusslin]

We are on a trip with elevation going up to 3500 ft. Going uphill with cruise set at 65 mph the RV slows down to about 53mph and is struggling to maintain speed. I tried to step on the gas but no more power to get as it was at max power. We are towing a Jeep grant Cherokee.
Is that normal for a Cummings 5.6l diesel? We had a sprinter diesel before and had no issue slowing down going uphill.

[TrailWayz]

Something does not sound right.

We have the I5 30FW and also tow a Jeep Grand Cherokee. We have had no issues maintaining speed in the mountains or steep grades and if we have to get on the gas it always seems to have the power we need to maintain or accelerate passed trucks or slower moving vehicles. We have been very impressed with the power and and engine performance of the Cummins Diesel.

If there is an issue, hopefully it is nothing serious or will self-resolve.

[vlamgat]

Sounds like you are not getting boost from the turbo charger? Do you have an engine check light on?

On a tow test, the stock truck was comparable to to the Duramax and both slightly inferior to the F350 with a 26,000 trailer going up the the Eisenhower pass and all 3 could maintain about 55. Our C&C chassis are derated but should not be that badly impaired.

Seems like a trip to the dealer is required but you might want to check for Codes first.

[msusslin]

Originally Posted by vlamgat

Sounds like you are not getting boost from the turbo charger? Do you have an engine check light on?

On a tow test, the stock truck was comparable to to the Duramax and both slightly inferior to the F350 with a 26,000 trailer going up the the Eisenhower pass and all 3 could maintain about 55. Our C&C chassis are derated but should not be that badly impaired.

Seems like a trip to the dealer is required but you might want to check for Codes first.

No engine check light on. Seems a trip to the dealer on deck.

[vlamgat]

Also check out the section in the Ram OM that starts on page 96. It allows you to look at a variety of engine parameters. The one you want to see is turbo boost. You should be seeing around 20+ psi or 1.4 Bar at full throttle going up hill.

[msusslin]

Originally Posted by vlamgat

Also check out the section in the Ram OM that starts on page 96. It allows you to look at a variety of engine parameters. The one you want to see is turbo boost. You should be seeing around 20+ psi or 1.4 Bar at full throttle going up hill.

Thank you for all your feedback.
What I understand so far is that if going uphill with cruise set at 65 mph the power of the 6.7 Cummings should be sufficient to maintain speed and even have more power available to speed up to pass other cars. Correct?
Our previous 3.0 L sprinter diesel was flying up hill with lots of extra power.

I did check the boost gauge while driving and it increased as it needed more power. However I did not notice the transmission to downshift as I would have suspected to increase RPM if needed.

[vlamgat]

Originally Posted by msusslin

I did check the boost gauge while driving and it increased as it needed more power. However I did not notice the transmission to downshift as I would have suspected to increase RPM if needed.

Did you activate the Tow/Haul mode switch?

[msusslin]

Originally Posted by vlamgat

Did you activate the Tow/Haul mode switch?

Did not and can't find how to activate the Tow/Haul mode on a 2020 Ram 5500? Please advise.
I read in the owners manual that going uphill cruise control should not be used as it will slow down going up hill. Is that what you guys do going uphill?

[vlamgat]

Originally Posted by msusslin

Did not and can't find how to activate the Tow/Haul mode on a 2020 Ram 5500? Please advise.
I read in the owners manual that going uphill cruise control should not be used as it will slow down going up hill. Is that what you guys do going uphill?

Should be a button just above the Aux buttons in the center of the dash. Says Tow/Haul - press to activate and press again to deactivate

[msusslin]

Originally Posted by vlamgat

Should be a button just above the Aux buttons in the center of the dash. Says Tow/Haul - press to activate and press again to deactivate

Only 3 buttons available. Fog light, battery and exhaust brake. To the left is the trailer tow break adjuster, which is not in use with a tow car, as far as I understand.

[vlamgat]

That's strange because the OM shows the Tow/Haul button as a standard feature but Fog lights are not even an option for the C&C.

That would imply your vehicle does not have a hitch and the tow package fitted? So you would have to use the ESL(?) electronic downshift manual feature to force the downshift and hold a lower gear.

[msusslin]

Originally Posted by vlamgat

That's strange because the OM shows the Tow/Haul button as a standard feature but Fog lights are not even an option for the C&C.

That would imply your vehicle does not have a hitch and the tow package fitted? So you would have to use the ESL(?) electronic downshift manual feature to force the downshift and hold a lower gear.

That seems counter intuitive to go to a manual shift mode when going uphill.

[milkman55]

What year model RAM 5500?
The 2019 and newer have 6 AUX buttons and then the Tow/Haul and Exhaust Brake just above.

[msusslin]

Originally Posted by milkman55

What year model RAM 5500?
The 2019 and newer have 6 AUX buttons and then the Tow/Haul and Exhaust Brake just above.

2020 Ram 5500

[milkman55]

This picture is out of the 2020 RAM 5500 brochure. Does you center dash not look like this?

[vlamgat]

That's what you should have. Somewhere out there on the web you can get a copy of the original delivery sticker and check whether it was built with the Tow Package. I believe that is a standard build requirement for Dynamax and it would be quite unusual for there to be a non spec truck used by them.

Obviously its not logical to downshift manually but your transmission is seeing sufficient torque at a lower rpm not to trigger the downshift automatically. During the road tests, I saw all 3 of the trucks downshift going up the Eisenhower Pass with the driver's foot planted. So that too is strange that you are not seeing that and its locked in 6th.

[msusslin]

Originally Posted by milkman55

This picture is out of the 2020 RAM 5500 brochure. Does you center dash not look like this?

That's what I have on my dash.

[vlamgat]

That is the Gen 4 version which did not have a Tow/Haul mode unless specified and that was not done with the 2017 models although I believe it was with the 2018 versions. Lower power too which would explain your experience. What boost levels were you seeing? The earlier versions of the C&C were lower rated than the models since 2019 which only went into build around mid year 2019.

[msusslin]

Originally Posted by vlamgat

That is the Gen 4 version which did not have a Tow/Haul mode unless specified and that was not done with the 2017 models although I believe it was with the 2018 versions. Lower power too which would explain your experience. What boost levels were you seeing? The earlier versions of the C&C were lower rated than the models since 2019 which only went into build around mid year 2019.

Not sure what boost level I had going up hill but as I was monitoring it it seemed to increase with more power needed. More than 1/2 of the gauge I was looking at in the dash control.

Please explain lower power? Is there different power levels for the 6.7 Cummings diesel engine? I read in the OM that going uphill the cruise control should not be used as it will slow down by up to 10 mph, which is what we saw. I love the adaptive cruise control on our 2020 chassis and have it on 80% of the time, as I find it a major safety feature.

[milkman55]

If you are on Facebook, post that picture in the Isata 5 FB group so others can comment. Never seen a dash like that on any RAM 5500. Is yours 4 wheel drive? Trying to figure out how it could be different than what we usually see.