Community Forums

Party Barge · 05-30-2006, 07:38 AM

I HAVE A NEW ITASCA HORIZON (06) 40' KD FROM WINNABAGO. IT SITS ON A FREIGHTLINER CHASSIS AND IS POWERED WITH A CUMMINS ISL 400 WITH A SIDE RADIATOR.
THE TEMPERATURE HAS REACHED 220 DEGREES SEVERAL TIMES AND I HAVE HAD TO DOWN SHIFT TO CONTROL IT.
I HAVE EXPERIENC WITH RV'S AND I'M CONCERENED WITH WHAT IS NORMAL FOR THIS TYPE OF UNIT.

I LIVE IN THE DESERT AND PULL A CAR.
THE OUTSIDE AIR TEMP WAS IN THE 90'S.
ON THE GRADE FROM PHOENIX TO FLAGSTAFF I HAD TO SHIFT INTO 3RD GEAR AND STAY AT 35 MPH TO KEEP MY TEMPERTURE DOWN.
I HAVE BEEN TO FREIGHTLINER AND NO TROUBLE CODES WERE REGISTERED.
HAS ANYONE HAD ANY EXPERIENCE WITH THIS TYPE OF UNIT? DOES THIS SEEM NORMAL FOR SIZE, WIEGHT, CONDITIONS FOR THE POWER PLANT?

Party Barge · 05-30-2006, 07:38 AM

I HAVE A NEW ITASCA HORIZON (06) 40' KD FROM WINNABAGO. IT SITS ON A FREIGHTLINER CHASSIS AND IS POWERED WITH A CUMMINS ISL 400 WITH A SIDE RADIATOR.
THE TEMPERATURE HAS REACHED 220 DEGREES SEVERAL TIMES AND I HAVE HAD TO DOWN SHIFT TO CONTROL IT.
I HAVE EXPERIENC WITH RV'S AND I'M CONCERENED WITH WHAT IS NORMAL FOR THIS TYPE OF UNIT.

I LIVE IN THE DESERT AND PULL A CAR.
THE OUTSIDE AIR TEMP WAS IN THE 90'S.
ON THE GRADE FROM PHOENIX TO FLAGSTAFF I HAD TO SHIFT INTO 3RD GEAR AND STAY AT 35 MPH TO KEEP MY TEMPERTURE DOWN.
I HAVE BEEN TO FREIGHTLINER AND NO TROUBLE CODES WERE REGISTERED.
HAS ANYONE HAD ANY EXPERIENCE WITH THIS TYPE OF UNIT? DOES THIS SEEM NORMAL FOR SIZE, WIEGHT, CONDITIONS FOR THE POWER PLANT?

Hitchhiker · 05-30-2006, 09:36 AM

Hello "Party Barge",

Welcome to iRV2, we're really glad to have you here as a new member and are looking forward to reading your posts about your RVing experiences and adventures in your Winnebago MH. You'll find a great bunch of folks on this site who are very knowledgeable of RVing, the rigs we use, and the places we go in them.

As you'll see, they're eager to help and share their knowledge and experiences with others.

I'm not a MH owner and have no direct personal experience with them, however I do recall reading here someplace that some of these diesel pusher's radiators are quick to fill up with dirt, dust, etc. I think the suggestion was to carefully wash out the fins, making sure it's good and clean.

Not sure if that's going to resolve the concern you have with yours but it's an easy and cheap fix to try.

Again, welcome to iRV2, we're glad you joined.

Also, did you know that typing in all caps on the Internet is perceived as shouting? Not sure if you meant to be 'shouting', but thought I'd pass that along just in case you weren't aware.

Good luck with the fix.

OldForester · 05-30-2006, 09:54 AM

I have a new Alpine 36' with the same engine and have driven it only 200 miles, over a steep hill or two, and notice it gets up to 200 degrees, which is the thermostat setting. Since the coolant boiling point on a 50/50 mix should be around 226 degrees, you are definitely approaching the limit.

Have you checked the temperature guage to make sure it's OK? It might not give an indication on the diagnostic computer. You could be having a guage reading too high compared to the actual temperature that the engine is running, or perhaps a temperature sensor that's not right.

Bob in Dallas · 05-30-2006, 02:07 PM

The cooling boiling point of a 50/50 mix may be 226 in free air, but under about 15 PSI of pressure it is about 250. If the unit runs at 210/220 under load in 90+ temp it is probably working as designed. A quick call to Cummins or the manufacturer should confirm a problem or ease your mind.

lwmuddy · 05-31-2006, 03:19 PM

The call to Cummins is the best way to be absolutely sure of your units limitations. If you get warning buzzers and/or lights it can be too late already. Don't let your automatic trans make the decision as when to downshift.

If you CAN NOT accelerate going up hill then back off, slow down and manually shift DOWN.

You are smarter then your trans.

John_Canfield · 06-01-2006, 04:56 AM

Hi and welcome to the forum and welcome from another Horizon owner!

Please turn OFF ALL CAPS BECAUSE THIS IS DIFFICULT TO READ - thanks.

You will find your answer in this recent thread. Let me know if you have any questions after reading the diaglogue.

Party Barge · 06-01-2006, 10:12 AM

Hi John, I read the thread. Very interesting. Right now my rig is at Freightliner in Las Vegas, they have inspected it and checked the fan. The service mangager in Las Vegas as well as a service person in Flagstaff stated that they thaught that the Isl was a egr motor (exhaust gas recirulation) and would run a little hotter than a non-egr motor.

I called Cummins customer service today and was told that the Isl with my serial number was not and egr engine. I asked about the fault codes and specificly when the high temp code would be registered. I was told that the engine will send the code at 208 degrees. I have been over 208 many time according to the Frieghtliner gauges and trip tek screen and have had the read outs flashing at 220 until I brought the temp. down below 215. The Cummins tech. also told me the the check engine light should come on when the high temp code is registered. Cummins recommeded that I take it to their shop if Freightliner can't figure it out.
It is sounding more like a communication issue between the engine and dash, but I want an answer before anything gets damaged.

By the way, my mode was off and I was down shifting manually. If I could have held the temperature in 4th, I would have never written to the forum.

Party Barge

John_Canfield · 06-01-2006, 06:08 PM

The Freightliner guy that looked at my "overheating" problem said the 222 degrees that the Freightliner Info Center reported never set a code in the Cummins electronics (he was in there and could look at the Cummins data.) There was no "check engine" light even though we were at 222 degrees briefly.

If you can't keep your temperature less than 210 or so by keeping the rpm up to 2,000 then I think something is amiss.

We just pulled a really long and steep grade yesterday going from Billings to Great Falls, Montana on I90; this has to the the longest and steepest grade we have ever had the coach on and with the rpm up to 2K we were never over about 208 degrees or so. I also saw the tranny temp the highest it has even been - it was in the center of the dial which is still normal (12:00 o'clock position); usually the needle is about 10:30 or 11:00 o'clock position.

We stopped at a rest area at the top of that pass for lunch and there was a poor guy next to me in a 5th wheel being pulled by a Chevy Duramax. I glanced over at his hood and I saw whisps of smoke coming out

.. There was also a tractor-trailer in the rest area with his hood up and being attended to by road-side service.

chris cross · 06-02-2006, 01:46 PM

Party Barge:
We make the trip from Page to Phoenix at least 6 times a year for medical maintainence. Also have the 400 ISL and find that the key to temp. control is to keep the rpm around 2000 on the grades on each side of the Verde Valley. I was going through a gallon of coolant during each round trip (300 mi) during the hot months and was also very concerned. After putting in a coolant recovery tank and keeping the rpms around 2000 on the grades we've had no more issue with coolant or temp.

Party Barge · 06-02-2006, 03:28 PM

I see your driving an Alpine. My friend is an Alpine driver as well and has good luck with unit cooling. I think right now that I'm looking at a Freightliner vs cummins is on gauge and trouble code comms.

chasfm11 · 06-03-2006, 04:27 AM

I have no experience with overheating problems like yours but thought that I would offer some "food for thought". Please accept it as just that.
1.Was your set-up properly designed for cooling? Before we bought our coach, the previous owner is reported to have and cooling problems. Freightliner had a maintenance history on our chassis where modifications had been made, the coolant replaced, etc. Have you considered putting some pressure on Winnebago? They are are the ones who put everything together.
2. By the time we bought our coach, we had the opposite problem - our engine wouldn't get warm. Cummins agreed to replace two thermostats in the engine. If noone seems to be able to figure out what is wrong, replacing the thermostats cannot hurt.
3. It sure sounds like your engine should be setting an alert but isn't. I'd be tempted to require that the sensor which is supposed to do that be replaced immediately. It might help toward diagnosing the problem.
4. I was a computer tech. My rule of thumb when I took a service call where I couldn't find the source of a problem was to "do something." I put parts in where I wasn't at all sure they were going to resolve the problem. I had a VW Rabbit with a A/C that kept leaking freon while under warranty. I kept taking it back and they would recharge the system, look for leaks and give it back, only to have it fail again. I invoked my "do something" philosophy with them. When they told me they couldn't find the problem the next time, I told them I wanted the compressor replaced. I told them the next time, they would be replacing the evaporator and then the condenser after that. They said "oh, we couldn't do that, it would be too expensive". They found the leaking hose two hours later and I never had a problem with the A/C the rest of the time that I owned the car. I do admit that it is possible to introduce new problems into the mix with this approach but sometimes the very thought of wholesale parts replacement spurs thinking and actions that wouldn't have been possible otherwise.

JMHO.

Party Barge · 06-03-2006, 06:40 AM

The rv is in the Las Vegas Freightliner shop right now. We took it into have them take a look at it. We also had a fuel gauge that was not working so they had to drop the tank to replace the sending unit. The plan on road testing the unit Tue. So we wait.

MrTransistor · 06-06-2006, 08:19 PM

Hi All,

Additional food for thought. In checking the Freightliner web site for the specifications of the radiators in the different models, I discovered that all units (Journey, Meridian, Vectra, and Horizon) from 03 through 05 use the same two row 15 fin per inch 1050 square inch radiator regardless of engine. For the 06 model year, the radiator size on all models (including the Tour and Ellipse) changed to a two row 15 fin per inch 1000 square inch radiator. Seems odd to me that the same radiator would be used for the Cummins ISB 300 HP, CAT 3126E 330 HP, CAT C7 350 HP, and Cummins ISL 400 HP engines. Each one would require different amounts of heat dissipation.

I believe the Cummins engines use EGR and it seems like they would have a higher cooling requirement per HP than non-EGR engines. On a cooling requirement per HP basis alone, the ISL would need 33 percent more cooling than the ISB. I'm curious to know if the overheating problems are only affecting the ISL equipped coaches. We have the CAT C7 350 HP engine, are living in New Mexico at or above 5000 feet with temperatures around 100 degrees with hills (mountains) to spare and with 42,000 miles on our coach, have had no overheating problems at all.

Can we hear from other owners with CAT or Cummins ISB engines? Maybe this should be brought up and escalated to Winnebago and Freightliner as a design problem that may require a retrofit to a larger radiator core for the ISL engine.