RV Trip Planning Discussions

Go Back   iRV2 Forums > POWER TRAIN GARAGE FORUMS > Cummins Engines
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
 
Thread Tools Search this Thread Display Modes
 
Old 06-23-2020, 02:45 PM   #1
Senior Member
 
JRPA's Avatar


 
Monaco Owners Club
Join Date: Aug 2008
Location: Las Vegas
Posts: 300
Overheating on slight Grades in Hot Weather

We have had problems with our 2007 Monaco Camelot (side radiator) 400 cummins ISL engine heating up since we purchased it in 2012. Generally we are able to maintain 210 degrees or less simply with slowing down (sometimes to 40 mph), down shifting and increasing rpm up around 2200. On a regular day on flat ground we stay within 185-195 temperatures with transmission generally within 5 or so degrees of the engine temp.

I have tried washing our radiator from front and back, checking coolant levels and almost never needs water but occasionally a quart or two. Checking DCH levels with ohm meter and less than .3 volts, cleaning radiator, radiator fan is hydraulic and the reservoir is full and fresh filters put in about a year back, but nothing has made much difference. The fan seems loud all the time, so I dont know if it is running the same speed all the time or increasing when it gets hotter. It does have a fan clutch and it seems to spin smoothly by hand, if that matters.

Recently, we drove from Yuma to Las Vegas and back in 100 plus temperatures. There are not really any severe grade on the route so that wasn't a factor. The engine ran fine until we would start one of many minor grades on the highway and temps would increase up to 222 (even with slowing down and down shifting to 4th) but occasionally hit 224 degrees when check engine light would illuminate and I would slow down more and go down another gear with rpms maintaining 2200. The engine temps always came down to the low 200 degrees quickly once I slowed down enough while maintaining rpms but some of that highway is 2 lanes and I was at 35 mph.

When I got home, I checked the engine and found the radiator cap missing and water level down about 3 quarts but still had water in the surge tank. I ordered a new 10# radiator cap and the following week we drove to Lake Tahoe and on the mountain passes (2 of which are over 7000 feet) I had to go all the way to 1st gear and 10mph to keep the temp below the 224 where the check engine light would illuminate. But as soon as I hit the top of the pass, the temps dropped to 185 in about 2 miles distance.

We are currently staying at Lake Tahoe and I have called Cummins in Sparks Nevada to make an appointment (July 7th) which gives me some time to do some trouble shooting. I am guessing it may have something to do with our fan speed and that is also what the cummins service tech mentioned. I have sprayed a high pressure washer (from a distance and low pressure) through the radiator to clean out any debris but it seems to be clean. I will try shining a flashlight through it tonight to see if the light penetrates the fins as I read from one poster.

Does anyone have any thoughts that might point me in the right direction? I am sure the Cummins visit will be measured in thousand of dollars that could possible be spent on other things if I could find the problem and fix it prior to my appointment date.
__________________

__________________

Bob & Pearl
www.youtube.com/justpassingthru
2007 Monaco Camelot 42' PDQ
JRPA is offline   Reply With Quote
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!

Old 06-23-2020, 02:48 PM   #2
Member
 
Join Date: Dec 2019
Posts: 81
The thermostat might not be opening all the way. ?
__________________

Mr Ted is offline   Reply With Quote
Old 06-23-2020, 02:50 PM   #3
Senior Member
 
JRPA's Avatar


 
Monaco Owners Club
Join Date: Aug 2008
Location: Las Vegas
Posts: 300
Quote:
Originally Posted by Mr Ted View Post
The thermostat might not be opening all the way. ?
Good Idea, I think I will definitely change the thermostats this week, a pretty easy project and could be the issue. thanks
__________________

Bob & Pearl
www.youtube.com/justpassingthru
2007 Monaco Camelot 42' PDQ
JRPA is offline   Reply With Quote
Old 06-23-2020, 02:57 PM   #4
Senior Member
 
Join Date: Jun 2017
Location: Bryan Tx
Posts: 615
Some coaches also have a thermostat valve that controls the fan speed. If yours is on the original T-Stat changing that would be a good shot at it
__________________
ď06Ē Beaver Patriot Thunder , 525 HP C13 Cat
MH 4000 Allison
42 ft Vicksburg, 4 slides
kenwyatt is online now   Reply With Quote
Old 06-23-2020, 02:57 PM   #5
Senior Member
 
Smitty77's Avatar
 
Join Date: Aug 2010
Location: Over the next hill, around the next curve...
Posts: 4,805
Thermostat check out is a yes. Also check the lower radiator hose to see if it soft/collapsing restricting circulation.

Please circle back and let us know what you find out, as it could help others in the future.

I will also share, that when we elected to flush our radiator, we changed to Peak Final Charge - and saw a drop in coolant temperatures. (While I feel flushing the radiator did not help, I do not feel it was restrictive. And I've heard other's say they've seen coolant temp drops due to changing to OAT based (Non SCA) coolants. I went with Final Charge, as it is readily available at many truck stops, like Flying J Travel Centers.

Best of luck to you,
Smitty

(Sparks Marina? - Spent a very hot 4th of July their about 3 years ago!)
__________________
07 Country Coach Magna Rembrandt 45' ISX600
Roo II was our 04 Country Coach Allure 40'
OnDRoad for The JRNY! Enjoy life...
Smitty77 is offline   Reply With Quote
Old 06-24-2020, 06:40 AM   #6
Senior Member
 
Burgy's Avatar
 
Join Date: Apr 2011
Posts: 249
does your coach have the wax valve to control the fax or the electronic control box.

if it's the wax valve you might it might have gone bad (rare).

Do you ever hear your fan running on high, dust clouds when going thru a campground?

how long has it been since you changed the oil and hydro filter?

Does the fan spin slowly at high idle?

how are the "rubber" seals between the radiator stack and the side of the coach
__________________
Lynn, Guy & Rocky

2004 Monaco Dynasty
Burgy is offline   Reply With Quote
Old 06-24-2020, 08:52 PM   #7
Senior Member
 
Happycarz's Avatar
 
Monaco Owners Club
Join Date: Sep 2007
Location: Scottsdale, AZ
Posts: 2,056
The electronic fan controller has been a weak link on the 2007 Camelot. Many folks with that controller have switch to the wax valve controller to get their temperature down.

Try doing a search in the Monaco section, for wax valves.
__________________
Harry

2008 Monaco Camelot 40' PDQ
Happycarz is online now   Reply With Quote
Old 06-24-2020, 10:02 PM   #8
Senior Member
 
vito.a's Avatar
 
Monaco Owners Club
Join Date: Oct 2009
Location: Tucson, AZ
Posts: 4,262
I agree with Harry. Many of us have had issues with the Sauer Danfoss electronic fan controller. It regulates the hydraulic fluid to the engine cooling fan and thus controls fan speed. The electronic fan controller is out of production but some have had it repaired (repair costs are usually over $1000).

Several of us have switched to the mechanical "wax valve" fan controller. This system was factory installed on coaches equipped with the Detroit 60 series engine and is a mechanical means to control the hydraulic fan speed.
Link to thread:
https://www.irv2.com/forums/f115/fan...en-376611.html

Having said all this, the Sauer Danfoss electronic fan controller is supposed to default to full speed fan when it fails. But, from your description it's worth looking into.

Another thing to check: There are supposed to be some rubber strips on the sides of the radiator and charge air cooler to prevent hot air from the engine compartment being pulled through the sides by the fan. The idea is to allow only outside air in through the radiator.
Another thing to check: The condition of your fan and hydraulic system. You can purchase an inexpensive tachometer and glue some aluminum foil to one fan blade and check RPM. It should go to hi-speed when you turn on the dash A/C.

Last, does it help your engine temp to turn off the dash A/C system going up hills?
I hope you get it figured out.
__________________
97 Monaco Windsor- Sold
07 Monaco Executive McKinley- Sold
04 Monaco Signature Chateau IV
vito.a is offline   Reply With Quote
Old 06-24-2020, 10:54 PM   #9
Senior Member
 
JRPA's Avatar


 
Monaco Owners Club
Join Date: Aug 2008
Location: Las Vegas
Posts: 300
Thanks everyone for the great suggestions, I plan to switch out the thermostat this week-end and our antifreeze SCA is fine but it has been about 5 years since it was changed out so will do that as well (once I get out of an RV park to where I can change it).

I do think our hydraulic fan controller may be malfunctioning and running at full speed all or most of the time as it seems loud and we always kick up a cloud of dust idling through campgrounds which has seemed odd but now kind of makes sense if the fan is going full bore even at idle.

My concern is, if the radiator fan is running at full speed the engine should be cooler not hotter so I feel there is most likely another problem. Also, I dont understand why it cools off so quickly when I increase RPM when I downshift (in some cases down to 2nd or even 1st gear) and in the case of when the "Check Engine" light comes on at 224 degrees, I pull over and put it in Neutral and increase RPM to 2000-2300 and it cools down to 215 or less within seconds. That indicates to me that the fan RPM is varying according to the engine RPM (so maybe it isnt on HI SPEED all the time?)

I am leaning towards the thermostat and antifreeze replacement but dont know where to turn when/if that doesn't work. I am very concerned that Cummins will just be chasing the problem with replacing expensive parts until they repair it or I go broke.

I went back into Cummins here in Sparks Nevada today and they are also leaning towards the fan controller but cant get us into the shop until July 7, So all your suggestions and links to other posters (most of which I have already read but all give insight) are so very helpful and appreciated.
__________________

Bob & Pearl
www.youtube.com/justpassingthru
2007 Monaco Camelot 42' PDQ
JRPA is offline   Reply With Quote
Old 06-25-2020, 06:12 AM   #10
Senior Member
 
KanzKran's Avatar


 
Join Date: Sep 2018
Posts: 1,089
Quote:
Originally Posted by JRPA View Post
It does have a fan clutch and it seems to spin smoothly by hand, if that matters.
This caught my eye and has me wondering. I've never seen a hydraulic fan drive system with a clutch. Is this normal? Is it the common temperature-controlled viscous fluid type that self-engages or stiffens when it gets hot? Or is it just bypassing around the loop through the anti-cav check valve, which would work in one direction only?

While I've never had a diesel pusher, I've been around a lot of machinery with hydraulic fan drives and have designed many such units myself, and never seen a clutch in concert with a hydraulic drive with speed control. So this one has me scratching my head and wondering if I haven't been around enough.
__________________
Tom & Jeri
2018 Coachmen Galleria 24T Li3
KanzKran is online now   Reply With Quote
Old 06-25-2020, 06:27 AM   #11
Senior Member
 
grindstone01's Avatar
 
Join Date: Oct 2017
Location: FULL TIMERS
Posts: 4,747
A 13 year old radiator could be plugged inside, especially if the coolant fluid was not changed on a regular 3 year cycle. You could remove the radiator and have it boiled out or just replace it. It don't owe you anything after 13 years of service.
Replacing a radiator is alot cheaper than new head gaskets which might be the next symptom of your over heating.
__________________
2018 Chevy DRW
2008 Carriage Cameo, F34CK3
Full Time since 2012
grindstone01 is online now   Reply With Quote
Old 06-25-2020, 08:24 AM   #12
Senior Member
 
JRPA's Avatar


 
Monaco Owners Club
Join Date: Aug 2008
Location: Las Vegas
Posts: 300
Quote:
Originally Posted by KanzKran View Post
This caught my eye and has me wondering. I've never seen a hydraulic fan drive system with a clutch. Is this normal? Is it the common temperature-controlled viscous fluid type that self-engages or stiffens when it gets hot? Or is it just bypassing around the loop through the anti-cav check valve, which would work in one direction only?

While I've never had a diesel pusher, I've been around a lot of machinery with hydraulic fan drives and have designed many such units myself, and never seen a clutch in concert with a hydraulic drive with speed control. So this one has me scratching my head and wondering if I haven't been around enough.
My mistake as I dont totally understand just how the fan works and I am sure you are correct with the terminology. I was trying to relay that the fan spins freely when the engine is not running and I was thinking the device that let if spin freely when not needed then spin up to approximately equal engine rpm would be called a fan clutch but apparently not. Sorry for the confusion on my part as I am simply a little bit over my head with this project.
__________________

Bob & Pearl
www.youtube.com/justpassingthru
2007 Monaco Camelot 42' PDQ
JRPA is offline   Reply With Quote
Old 06-25-2020, 08:33 AM   #13
Senior Member
 
JRPA's Avatar


 
Monaco Owners Club
Join Date: Aug 2008
Location: Las Vegas
Posts: 300
Quote:
Originally Posted by grindstone01 View Post
A 13 year old radiator could be plugged inside, especially if the coolant fluid was not changed on a regular 3 year cycle. You could remove the radiator and have it boiled out or just replace it. It don't owe you anything after 13 years of service.
Replacing a radiator is alot cheaper than new head gaskets which might be the next symptom of your over heating.
I am guessing the radiator could very well be clogged after 13 years of service, but if it is clogged, I wouldn't think it would be able to cool down so quickly (much less than a minute) when I slow down and downshift to increase rpm up over 2000 rpm's. I dont have any issue with having to slow down and increase rpm's but on steep hills, I have to shift down to 2nd and recently 1st to get it to cool down.

I would happily replace the radiator if it thought it was the problem(and have read post where that solved the overheating for a gentleman in a RV just like mine) but I don't want to just swapping items out to see if something is not working properly until I stumble onto a fix. I am sure that is what Cummins will do for me, but I will run out of money well before they replace everything folks have suggested I replace. Although your suggestion might very well be the solution and be what we end up doing.
__________________

Bob & Pearl
www.youtube.com/justpassingthru
2007 Monaco Camelot 42' PDQ
JRPA is offline   Reply With Quote
Old 06-25-2020, 08:46 AM   #14
Senior Member
 
KanzKran's Avatar


 
Join Date: Sep 2018
Posts: 1,089
Quote:
Originally Posted by JRPA View Post
I was trying to relay that the fan spins freely when the engine is not running and I was thinking the device that let if spin freely when not needed then spin up to approximately equal engine rpm would be called a fan clutch but apparently not.
No sweat. I thought there might be more to this system, which would also mean another potential failure point to investigate.

Does the fan spin freely in both directions, by hand? There's a check valve that should be closed as the pump drives the fan motor, but if the fan tries to spin faster than the fluid column is moving, the check valve allows the fluid to loop around. Prevents cavitation (boiling of the oil, basically) and sucking air in through seals that aren't intended to prevent that.

But that means the fan should only spin relatively freely in one direction with the engine off. If it spins in both directions, it's because the anti-cavitation check valve isn't closed, and oil is bypassing the fan motor when it's being driven by the pump. Something quick and easy to test, at least.

Page 4 of this Parker marketing fluff shows their simplest system, with the anti-cavitation check next to the motor. You can see that oil flows only one way through it (backwards), which is why the fan spins by hand in it's working direction, but not the other way. Or shouldn't spin backwards, at least. I don't know who made your system, but I've never seen one that didn't have such a check valve, including generator drives and just about every other motor system where a sudden drop in pump speed or flow output (for variable pumps) would result in the spinning load to over-run the fluid column.

https://www.parker.com/literature/Hy...ns%20Guide.pdf
__________________

__________________
Tom & Jeri
2018 Coachmen Galleria 24T Li3
KanzKran is online now   Reply With Quote
Reply

Tags
heat, heating, light, overheating



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Overheating on steep grades Rob1128 National RV Owner's Forum 7 07-10-2020 07:06 AM
Overheating slight grade - ISB 6.7 finnaz Cummins Engines 22 06-02-2017 01:21 PM
Slight Smoke From Aqua-Hot OB-One Class A Motorhome Discussions 3 10-12-2014 07:10 AM
Slight Power Drain? CSX4350 Newmar Owner's Forum 6 02-21-2008 06:05 AM
Slight overfill an an oil change. RCtime Winnebago Industries Owner's Forum 5 01-27-2008 08:24 AM

» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 07:46 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
×