|
|
10-16-2018, 11:29 PM
|
#1
|
Senior Member
Tiffin Owners Club
Join Date: Aug 2016
Posts: 184
|
Uphill trek
We have a 43’ 2010 Allegro Bus. It has an ISL9 Cummins 450hp motor and 6 speed Allison automatic tranny. We tow a Jeep Grand Cherokee.
We overheated once going up a 25% grade while towing the Jeep. Since then I had the radiator flushed and new fluid put in. I have a new air filter and radiator coils flushed.
We’re on a trip out west and I’ve noticed our rig will still approach overheating on long steep grades. It’s not quite gotten into the red but it was close. The transmission stayed in 5th gear and rpms stayed below 2k
We’re about to run I17 from Phoenix to flagstaff, AZ. It’s about 80 miles and 6000’ rise. I’m looking for advice on making the run and not overheat Should I unhook the toad and have the wife drive separate ?
Appreciate any guidance provided
__________________
Thanks, George
2010 Allegro Bus 43QRP
|
|
|
|
Join the #1 RV Forum Today - It's Totally Free!
iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!
You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!
|
10-17-2018, 01:45 AM
|
#2
|
Registered User
Join Date: Jul 2016
Posts: 1,042
|
Quote:
Originally Posted by glsponchos
We have a 43’ 2010 Allegro Bus. It has an ISL9 Cummins 450hp motor and 6 speed Allison automatic tranny. We tow a Jeep Grand Cherokee.
We overheated once going up a 25% grade while towing the Jeep. Since then I had the radiator flushed and new fluid put in. I have a new air filter and radiator coils flushed.
We’re on a trip out west and I’ve noticed our rig will still approach overheating on long steep grades. It’s not quite gotten into the red but it was close. The transmission stayed in 5th gear and rpms stayed below 2k
We’re about to run I17 from Phoenix to flagstaff, AZ. It’s about 80 miles and 6000’ rise. I’m looking for advice on making the run and not overheat Should I unhook the toad and have the wife drive separate ?
Appreciate any guidance provided
|
Is fan RPM tied to engine speed? If so you could try downshifting to a lower gear which would increase engine RPM and move more air through the radiator.
|
|
|
10-17-2018, 02:04 AM
|
#3
|
Senior Member
Join Date: Dec 2016
Location: So Cal Wine Country
Posts: 702
|
It would be a good idea to disconnect and transfer any weight you can to the toad as a workaround. We just came down from Flagstaff last week where we got some overnight snow, and temps are even colder this week which should help as well, and of course take your time making the climb.
For reference, the 400hp ISL rear radiator in our 40' Newmar Ventana barely registered above normal temperature on the climb to Flagstaff, so you'll obviously want to get your cooling system further checked out ASAP.
__________________
Bill
2014 Newmar Ventana 4037, XCR Tag Axle, Cummins ISL, All-electric
|
|
|
10-17-2018, 04:13 AM
|
#4
|
Senior Member
Join Date: Jul 2014
Posts: 35,317
|
Shift it to 4th and see what happens.
25% grade ?
|
|
|
10-17-2018, 06:08 AM
|
#5
|
Senior Member
Join Date: Oct 2018
Posts: 232
|
overheat
Quote:
Originally Posted by glsponchos
We have a 43’ 2010 Allegro Bus. It has an ISL9 Cummins 450hp motor and 6 speed Allison automatic tranny. We tow a Jeep Grand Cherokee.
We overheated once going up a 25% grade while towing the Jeep. Since then I had the radiator flushed and new fluid put in. I have a new air filter and radiator coils flushed.
We’re on a trip out west and I’ve noticed our rig will still approach overheating on long steep grades. It’s not quite gotten into the red but it was close. The transmission stayed in 5th gear and rpms stayed below 2k
We’re about to run I17 from Phoenix to flagstaff, AZ. It’s about 80 miles and 6000’ rise. I’m looking for advice on making the run and not overheat Should I unhook the toad and have the wife drive separate ?
Appreciate any guidance provided
|
Get your RPMs up , it should run cooler
|
|
|
10-17-2018, 06:17 AM
|
#6
|
Senior Member
Join Date: Apr 2008
Location: On the Road
Posts: 1,223
|
Downshift to 4th and slow down. On especially long steep grades I sometimes have to use 3rd
__________________
Dan & Arlene
2005 Monaco Dynasty Diamond IV
Chasing the good weather
|
|
|
10-17-2018, 06:33 AM
|
#7
|
Senior Member
Join Date: Aug 2016
Location: Pa
Posts: 648
|
Five million miles behind the wheel of a diesel(yes I'm one of those damn truck drivers), if it starts to get hot down shift and back off the throttle. The lower gear will allow you to ease off the throttle and maintain 2000 rpm. You may loose 5 mph, but your diesel will thank you.
Tom
__________________
2004 Coachman Santara 3480DS Workhorse w-22 Ultra Rv tune with Banks headers, Koni shocks
Retired OTR driver ATA 5 million mile safety award
USMC Vet 1968-1972
|
|
|
10-17-2018, 08:13 AM
|
#8
|
Senior Member
Country Coach Owners Club
Join Date: Jan 2011
Posts: 1,204
|
I had all my stacked radiators seperated, cleaned, reassembled, and the sending units (sensors) replaced. I have found the downshifting to solve many of my too hot issues. I also go a Silver Leaf System and found that my "too hot" problems were analog gauges that were off 10-15 degrees. What I want to know is where did you find a 25% grade hill? The steepest I've seen is 10% but that was only for less than a mile.
|
|
|
10-17-2018, 08:20 AM
|
#9
|
Senior Member
Tiffin Owners Club
Join Date: Aug 2016
Posts: 184
|
Quote:
Originally Posted by Sonic
It would be a good idea to disconnect and transfer any weight you can to the toad as a workaround. We just came down from Flagstaff last week where we got some overnight snow, and temps are even colder this week which should help as well, and of course take your time making the climb.
For reference, the 400hp ISL rear radiator in our 40' Newmar Ventana barely registered above normal temperature on the climb to Flagstaff, so you'll obviously want to get your cooling system further checked out ASAP.
|
Was that with your toad connected and no gear over rides ?
__________________
Thanks, George
2010 Allegro Bus 43QRP
|
|
|
10-17-2018, 08:22 AM
|
#10
|
Senior Member
Tiffin Owners Club
Join Date: Aug 2016
Posts: 184
|
Quote:
Originally Posted by pumper9x9
I had all my stacked radiators seperated, cleaned, reassembled, and the sending units (sensors) replaced. I have found the downshifting to solve many of my too hot issues. I also go a Silver Leaf System and found that my "too hot" problems were analog gauges that were off 10-15 degrees. What I want to know is where did you find a 25% grade hill? The steepest I've seen is 10% but that was only for less than a mile.
|
The 25% grade was at amicola falls on GA. Beautiful place. I was very new driver at time and never thought a thing about the coach not wanting to make the climb
__________________
Thanks, George
2010 Allegro Bus 43QRP
|
|
|
10-17-2018, 09:49 AM
|
#11
|
Community Administrator
Tiffin Owners Club
Join Date: Sep 2013
Location: DFW, Texas
Posts: 21,151
|
As mentioned, keep the RPMs above 2,000 by downshifting. Also, your radiator fan should have two speeds. When the temperatures reach around 210, you should hear the fan go into high speed mode and the temps drop. If it's not doing that, then you may have a bad fan controller.
__________________
2017 Phaeton 40IH XSH Maroon Coral - Power Glide Chassis with IFS
Previous '15 Tiffin Allegro RED 38QRA and '06 Itasca Sunrise 35A
'16 Jeep JKU Wrangler Sahara or '08 Honda Goldwing
|
|
|
10-17-2018, 10:30 AM
|
#12
|
Senior Member
Join Date: Dec 2016
Location: So Cal Wine Country
Posts: 702
|
Quote:
Originally Posted by glsponchos
Was that with your toad connected and no gear over rides ?
|
Yes, Honda CRV connected and no gear overrides
__________________
Bill
2014 Newmar Ventana 4037, XCR Tag Axle, Cummins ISL, All-electric
|
|
|
10-17-2018, 10:47 AM
|
#13
|
Moderator Emeritus
Join Date: Jan 2000
Location: West Palm Beach, FL. USA
Posts: 27,519
|
I'm skeptical about the need for downshifting on a modern turbo-diesel engine in a motorhome. In most recent diesel-pusher chassis the fan is computer controlled and not really rpm dependent. Downshifting may help, but it shouldn't be necessary. I think you have something wrong with your cooling system, perhaps with the fan control or maybe some crap embedded between the layers of the radiator/CAC/AC_condensor.
Amicola has about a mile of 25% and averages more like 13% over the two+ mile length. Steep, but ought not to be a severe problem for the coach cooling system. Your engine can run comfortably at 210 over short distances like that, and the tranny should stay at or below 200 as well. Even 205 is ok for short periods.
I don't know if your Bus has the tiffin chassis or Freightliner and I'm not sure what Tiffin did for a cooling system on it. If Freightliner, it is definitely a multi-speed fan controlled by the ECM. Also, is it side radiator or rear? Some of the Allegro Buses used a rear radiator with the ISL and [in my opinion] they are marginal on cooling capacity.
I would not expect it to got hot at all on that gradual 80 mile clim.
__________________
Gary Brinck
Former owner of 2004 American Tradition and several other RVs
Home is West Palm Beach, FL
|
|
|
10-18-2018, 09:22 AM
|
#14
|
Senior Member
Join Date: Feb 2013
Location: Sedona, AZ
Posts: 2,989
|
I would only do a 25% climb on an ATV. But the drive from Phoenix to Flagstaff won't give you anything steeper than 6-7%. It will be cold in Flag though.
__________________
Shell Bleiweiss
2014 1/2 Thor Challenger 37KT
Sedona, AZ
|
|
|
|
|
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
|
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
» Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
|