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JLAppel · 03-15-2014, 04:07 PM

I have a 2011 Winnebago Tour 42QD on as Freightliner XL Chassis. Since new, I have experienced a periodic overheating problem usually associated with freeway driving and then pulling off into city traffic wherein the coach overheats to the point of engine shutdown. A couple of minutes cool down, restart and high idle usually puts me back on the road within 5 minutes but thereafter, depending on traffic, the same issue persists. An early venture to Cummins resulted in an opinion that there was a "bubble" in the original coolant level. Later, a Freightliner dealer charged me $1500 to remove non-existant material between the fan and radiator plus, at my insistence, replacement of the thermostat. Problem still exists. I can drive 400 miles steady on a freeway, pull off into the city, and the coach overheats shortly thereafter. Any one experiencing similar Cummins circumstances with this motor?

Steve COH · 03-15-2014, 05:18 PM

No, that is not right.

What temperature range do you see in normal driving? I'm asking to see if the fan is engaging as it should.

I had the fan engaging all the time when a wiring harness came unplugged, and although unlikely, I wonder if your fan controller could be keeping it off all the time.

YC1 · 03-15-2014, 07:02 PM

Side radiator or rear? If side, the fan may not be coming on properly.

I would change the thermostat again myself. Get your engine serial number and call Cummins to get the current model thermostat. A new thermostat can be defective or they may not have changed it. With the old one out put it in boiling water to see if it opens properly..

If you have a rear radiator have you cleaned it?

HicksRA · 03-15-2014, 07:20 PM

If you have a rear radiator with a clutch fan, I'd have the clutch checked.

gemini5362 · 03-15-2014, 10:05 PM

Quote:

Originally Posted by JLAppel

I have a 2011 Winnebago Tour 42QD on as Freightliner XL Chassis. Since new, I have experienced a periodic overheating problem usually associated with freeway driving and then pulling off into city traffic wherein the coach overheats to the point of engine shutdown. A couple of minutes cool down, restart and high idle usually puts me back on the road within 5 minutes but thereafter, depending on traffic, the same issue persists. An early venture to Cummins resulted in an opinion that there was a "bubble" in the original coolant level. Later, a Freightliner dealer charged me $1500 to remove non-existant material between the fan and radiator plus, at my insistence, replacement of the thermostat. Problem still exists. I can drive 400 miles steady on a freeway, pull off into the city, and the coach overheats shortly thereafter. Any one experiencing similar Cummins circumstances with this motor?

that is a 3 year old maybe 4 year old coach. How long is your cummins warranty. You might want to look at the warranty information that came with your coach

JLAppel · 03-16-2014, 12:47 PM

The radiator and fan are rear mounted. Freightliner completely removed the radiator from the coach to ascertain if there was something that had sucked up between the radiator and fan (a possibility according to Freightliner. Not, however, in this instance). They flushed, power washed, refilled with fresh antifreeze, reassembled, dyno'd and assured me the fan clutch and thermostat was operating normally.
I also suspect the fan clutch. The perplexing part is that it is a periodic occurrence. And of course it happens at the worst time. When the warning bell goes off, there is only about 20 seconds to get off the road. The computer just shuts the engine down - usually right in the middle of the road. Then, after a very few minutes, restart the motor and bring the rpm up. Cools down quickly, warning light goes out and I can continue on my way - sometimes long distances before it occurs again and sometimes very short distances. If I get on the highway right away following an incident, it usually runs normal. When I get stuck in traffic is when the problem persists, especially following a long highway stint.

smlranger · 03-16-2014, 01:12 PM

Removing the radiator to see if there was something between the fan and radiator would be totally unnecessary. You can view the fan and the cooling pack by looking into the fan shroud, either from under the coach or overhead access from inside the coach. I believe you must have meant they thought there might have been something sucked into the space between the charge air cooler and the radiator. To clear that, radiator removal may have been necessary.

Has this been an issue since you got the coach?

bertman · 03-16-2014, 02:08 PM

When you say it cools rapidly after a restart, would make me think its a water pump problem. Did they replace the pump? Don't know how you would check it - you need a good Cummins shop!

Bumps · 03-16-2014, 02:27 PM

We had the "bubble in the coolant" problem a while back. ISL would overheat while under more stressful circumstances. Problem started after a radiator flush. Easy to diagnose, tho -- you could stand near the radiator and hear a pretty loud gurgling. Had it flushed again and problem solved. Do you hear gurgling at the radiator? Could be an easy fix (we hope). \ken

targaboat · 03-16-2014, 02:40 PM

Fact, system is not getting coolant flow or air flow during slow engine speeds. There are air flow tests to determine the air flow at any engine speed.

There are pressure tests to determine water flow. Get both of these done before anything more is done which you have to pay for. It appears you already have become suckered for the $1500 although if you insisted on the thermostat you might have contributed to that issue.

Then come back here and tell us the results in order to get solutions. Or, get with an honest and skilled service center which should be doing the whole job the whole job to begin with. A person must be an active party to their service work or get screwed.

Smitty77 · 03-16-2014, 02:46 PM

Sorry to hear of your problems, and not fun to have a coach shut down on you in a traffic condition (or anytime for that matter).

I hope a moderator will move this to the Cummins section, as some more Cummins people may be able to help.

I wonder if you have a faulty temp sensor, that occasionally sends a bad signal indicating High Temp? The computer will do what it is supposed to do, and protect the engine. The 'it happens sometimes' is the variable that makes me thing it is something electronic.

That being said, is this mostly in stop and go traffic situations? Dropping a gear to keep RPM's higher may help on this. Coupled to added heat build up, if the Allison is hunting back and forth between gears too - this will heat up the trans, which coupled to the engine could add heat too. Dropping gears, would help in both cases.

You might get a infrared heat temperature gun, not that expensive. And keep a log of actual heat read when shooting the same hose (Hose from block to radiator). If you see the same temp range after what you consider normal stop and go driving. And then get the same reading when the computer shuts you down, this could give you a better clue. (Bad temp sensor if heat ranges are the same. Or bad thermostat or water pump if heat ranges are truly that much higher.)

Either way, I would go to a Cummins shop on this. Not saying anything bad about Freightliner, but Cummins engine go to a Cummins shop. Especially if still under warranty.

Best of luck to you, and please update what you find out!
Smitty

targaboat · 03-16-2014, 03:44 PM

Good suggestion on the temp sender and the infrared meter. Better than my suggestions at this point.

pmpurcell · 10-12-2016, 02:56 PM

Did you ever get this problem fixed?

JLAppel · 10-16-2016, 11:32 AM

I am extremely happy to report that in he 2 1/2 years since the original posting, the issue has been very simply (and inexpensively) resolved. I followed the suggestions of several contributors and purchased a gallon of approved antifreeze. Added coolant to the top of radiator (right up to the bottom of the cap. Problem has not reoccurred since. As I understand the situation, the low coolant sensor is located in such a position that when the front of the coach elevates (like going up a steep grade) the coolant level drops below the sensor level triggering the alarm and subsequent shutdown. Filling the radiator past the maximum level fill line allows the coolant to maintain a level above the sensor. Before going to any great mechanical expense, I suggest this remedy - it has worked for me. As stated earlier, I have not had a single repeat occurrence in over 2 1/2 years.