98 Monaco N14 Cummins 525 overheating problems

[mdereyes]

Hello. This is my first post. I have a worsening problem with my coach. Engine cooling has been a problem since I bought it. On the first trip, it blew a hydraulic fitting and I lost 5 gallons of AW-46. In addition to the mess, the hydraulic fitting had to be reproduced by my maintenance provider, because none were available anywhere. My coach apparently has the wax hydraulic controller for the engine fans. The fans aren't working. At start up, the rear fan rotates slowly but does nothing else. The temperature reaches 180F, my new thermostats open, the temperature is ok until I begin to pull more than 10psi of boost, then the temp climbs to 220 and more. I have not moved the coach in two months because every time I get 40 miles east of where it broke, the overheat condition begins. I am getting desperate. ECU shows no codes, looking to check and tighten exhaust and turbo inlet. I am trying to avoid a 600 mile tow to my home base. The engine uses the Cummins dual aftercooler/radiator and it is not doing the job. Has anyone gone to electric fans? The side radiators are new, and the coach ran warm, but didn't overheat before. Does anyone know if the fans blow out or in toward the coach? Any good suggestions would be appreciated.
Thanks!

[Steve Ownby]

I’m guessing that either the wax valve controller is bad or the hydraulic pump isn’t moving enough fluid. The wax controller is pretty reliable and should default to “wide open fan operation” if it fails. It’s also possible that it’s failing in some other manner. Some have even been hooked up backwards.

Call this company and talk to one of the principals:

http://www.source-1mfg.com/

They both most likely worked for Monaco in the Roadmaster Chassis operation when your coach was built. They also manufacture an after market wax valve system. They are very knowledgeable and helpful to coach owners.

[MSHappyCampers]

Hi ! Welcome to IRV2! We're sure glad you joined the gang!

Not a mechanic so can't help with the problem! Keep her between the ditches!

Good luck, happy trails, and God bless!

[Mr_D]

from WA State!

[ThePowells]

[mdereyes]

Thank You to Mr. Ownby. Also Thank You for the welcome from Joe and Annette, Mr. D,and the Powells. Great group to be a part of.
Will post the outcome when I am sucessful.

[Clomok]

Have you checked the water pump? How is the other radiator? Cleaned out the CAC and Radiator/ free of dirt and debris? I’m not sure of the side fan but would assume they blow outward. When you replaced the thermostat did you do a coolant flush also? Some drivers like running block sealer/leak stop and that can compound issues. What did the old coolant look like? Last question haha...what is the temp getting to? I maintained a commercial fleet with N14’s all of them ran at 200 empty

[guardrail53]

"Has anyone gone to electric fans? The side radiators are new, and the coach ran warm, but didn't overheat before. Does anyone know if the fans blow out or in toward the coach?"

To your first question, Yes, My 1996 Monaco Windsor 8.3 ISC manual, not electronic motor has two electric fans that have been mounted to the outside of the stack between the CAC and the louvers. It was done by the previous owner, and I have never heard the stock fan kick on? It runs between 180 and 200 and never gets over 200/205 tops! I have been from Florida to upstate NY, pulling a toad, and it never gets hot!
A N-14 is almost twice as big as my 8.3 Cummins, so it is going to require a lot of cooling! I had one in my semi, and when I had a new crate motor put in it, I had the radiator rebuilt with 4 rows instead of the 3 row that came stock!

Second question, the fans blow in towards the motor, and if working, will suck a piece of paper to the louvers, and it will stay!

I would think you will not have room to put electric fans on the outside of your stack, because your radiator will have more rows than mine, for the bigger motor, just a guess? Mine just barely fit!
I think your best bet is to call the guys at, Source Engineering Inc | Custom RV Chassis | Eugene, OR
As Steve suggested!

Good luck! When you get that baby running cool, it will be a beast! Rail!

[mdereyes]

Clomok, Thank You. Water pump is ok, charge cooler and Radiator are new. It has run 195 to 220; however we recently found that the wax valve for fan control was bypassed to run full speed all the time. The real problem occurred when a hydraulic fitting on the fan inlet broke and blew all the hydraulic fluid out. I image all Monaco coaches from 1997-2000 are configured the same. When the fitting blew it blew out the flow divider and because there are no hydraulic fuses took the power steering too. Now that the new (manufactured by machine shop) part is in it, I am trying to find a flow divider and get the fans restored. So far, no luck. I just don't want to drive the 40 miles and turn around to go back. Each time the heat built until the buzzer and light came on. It has hit 240F once. So until I can get it to my home base maint., Source Engineering has been a bright spot. If I were wealthy, I would fly in a tech and have him/her look it over. 40+ yrs of flying have taught me that one is literally dead without good maintenance. Steep learning curve.

[mdereyes]

Guardrail 53, Thank You. You are right, I have had the coolant changed, done a pressure test, done everything I can think of, to help. Source Engineering will be the key. I think a trip to Oregon is in the near future, if the coach can get me home. I hope I don't have to buy a new Hyd pump and flow divider; I feel that I will have to replace the wax valve, because it was bypassed to begin with. Doesn't bode well.

[mdereyes]

It is now mid April and the coach continues to cause me trouble. I have replaced the splitter valve, bought a new fan motor, installed and blown the new fan motor seals, and thrown out at least 14 gallons of AW 46 hydraulic fluid. The hydraulic motor does not currently have a Sauer-Danfoss identification, and very few people outside of Source RV, Colton Truck Terminal, NW RV supply or Arizona RV salvage have been able to help. Parts and information are hard to come by. After installation last Saturday, the unit ran fine until I drove it to the car wash in preparation for going home. Once the RPM hit 1900, a car drove up next to us shouting about a massive diesel leak! My heart sunk because it was not diesel, but hydraulic fluid. I barely got it back 5 miles away before the power steering quit. My maintenance guy and I are at wits-end. So we will try a relief/bypass back as soon as we know what the max pressure is on the motors. Because this is a pre-REV group coach, I get very little help from them. I will post again next month on try #4.

[guardrail53]

I think I would go to a semi truck parts yard, and get a Horton elect clutch fan setup off a Freightliner/Pete/Kw and wire up a switch to your dash, and when it starts to get hot, kick it on! You will have to fab up a mounting setup out of some heavy metal, as the one's on semi's are mounted to the front of the motor, but I think it could be done! These are still belt driven, so a pulley setup would have to be fab'd, which could post some problems too, getting it to work! I know some of the side radiator coach's have a belt driven fan! And I would bypass the hyd. setup altogether!
Or you could measure from the outside of your radiator stack to the outside of your MH side wall, and build a Electric Fan setup to work also! You might have to remove the louvers, etc., or fab up the setup to mount on the inside of the stack, pulling the air through! They make some pretty nice elect. fan setups now days!
Mine has been done with the elect. fans (2) on the outside of the stack, by the PO of my coach, and they had to remove the top 2/3rd's of the louvers to get them to fit! They fabricated some very heavy hardware cloth like material and painted it to match the side of the coach! Mine never gets above 200*, and I have ran all up and down the east coast mountains!
Which ever way you go, hope you get it figured out! Rail!

[beenthere]

if that is a rear radiator style coach then i bet ,like i had to do, is clean the radiator and charge cooler,, used lots of dawn even under bed and sprayed while engine running to get in there.. i used pressure washer ,and careful to be straight on the fins and not to close. and i got a #$%^ load of dirt and grease

[Duoglide1]

Mdereyes I would suggest to go to the owners corner section here on iRV2 and click on Monaco and start an inquiry there. Some of those folks have the same coach or have had the same issues. Most of them are quick to offer suggestions. I spent a lot of time there when I had my Monaco. Good luck and welcome aboard.