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Old 02-21-2015, 03:39 PM   #15
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Sure could be flaky gauge readings, but does not sound like it.

Steve O's advice to get the fluid sample is both inexpensive, and would tell you quite a bit about the actual condition of the cooling system. Sure would be a prudent step to take.

I also know that when I changed over to Final Charge, my all around temperature ranged dropped down some.

And in addition to these steps, I'm a fan of having as much accurate info on engine condition as possible. The Silverleaf PC option is not all that expensive in the scheme of DP ownership. And it sure provides much better and more accurate info then the standard dash gauges. As mentioned, I might just show that your chasing a non problem. Though the temperatures you reported seemed to indicate to me that the gauges were not completely in error.

Very possible that you have a mix of conditions too! So it makes it easy (NOT!) to figure.

Good luck on your next few moves, and please circle back and let us know root cause (if any).


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Old 02-23-2015, 08:10 PM   #16
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Cummin ISL-400 overheating

Something a little different to check...this happened to me with our Mandalay. This is also a Freightliner chassis with the side radiator and the ISL 400.

The exhaust clamp at the exhaust side of the turbo came loose. This allowed the exhaust pipe to move away from the turbo about an inch, resulting in a massive exhaust leak...right behind the radiator! All those hot exhaust gasses swirling around under there disturbed the air flow through the radiator. The radiator was still pulling clean air from the outside, but on the output side of the fan, that cooling air met the exhaust gasses and could not clear properly.

The symptoms were that the engine would cool OK on level ground, but a long hill would cause an overheat, even if I shifted down to a lower gear to keep the revs up.

When I discovered this problem and got it fixed, the overheat problem went away.

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Old 02-23-2015, 08:35 PM   #17
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I, too, had the over-heating problem on my 400ISL. Had to stop and cool down while climbing I70 westbound into the Rockies. Again and again. Did that three times and then took it to a local shop. Diagnosis was a broken lip (it was hidden under the radiator cap) on the top of the plastic surge tank. Replaced the plastic tank with a metal one and the over-heating problem went away. Was more frustrating than it cost in $$$ to repair. Ugh! \ken
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Old 02-24-2015, 04:48 PM   #18
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Two things you don't mention. What is your RPM when you overheat and at what altitude.

You should operate your ISL at ~2000rpm and about 80-85% of your max boost when pulling grades. You should down shift until you achieve that operating condition.

I left Colorado last September and went eastbound to the Eisenhower tunnels. I run 2k rpm and 20lbs boost and water temp was 192F. 22lbs boost and it went to 198F. Because of the low air density temperature issues show up quickly. The tunnels are at ~11kft.
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Old 02-24-2015, 05:22 PM   #19
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I would change the thermostat out even though they claim it was opening. Inexpensive and easy to do. The original has been replaced by a newer design. It may not be opening fully. Put the old and new one in a pan of water and heat it up. Watch as they open. You may see a difference.
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Old 02-24-2015, 06:46 PM   #20
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Hope I am not providing obvious info but I had an overheat problem on long pulls in my 2004 Winnebago with CAT c7 engine. It was a rear radiator. Externally, the radiator fins looked clean but the radiator in my coach was a combination of radiator and "charge air cooler" which looked like a second radiator behind the first one. This was noted in one reply above. When I took the engine cover off (from inside) and inspected the front side of the composite radiator I saw that 75% of the fins were clogged with a thick oily film. In my coach the engine breather tube exhausted an oily vapor which was sucked into the radiator fan housing and was deposited on the front face of the composite radiator. Dust stuck to the oil and the film clogged the radiator.
Before you pull the radiator pls check the inside face to see if it might be clogged. If this is the case, a thorough cleaning with 50% simple green could solve your problem as it did mine. I found that the sludge could not be cleaned from the outside but required under the coach and above the engine cleaning.

On newer coaches, the crankcase is closed and the "slobber" tube that exhausts oily vapor does not exist. Check earlier posts on thread below.

"2004 Journey with CAT 330hp overheating on long pulls"

hope this helps,
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Old 05-30-2015, 05:52 PM   #21
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A lot of Alpines being used and not a lot of problems with over heating so I don't think radiator size a issue. WRV was known for using quality/adequate size equipment. Cat had some problems with their aluminum radiators. Lots of great info, recommend start by replacing thermostat and go from there but gauge accuracy could definitely be the issue.. Good Luck, Great Coach..
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Old 05-30-2015, 05:58 PM   #22
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Originally Posted by Mklbrook2 View Post
A lot of Alpines being used and not a lot of problems with over heating so I don't think radiator size a issue. WRV was known for using quality/adequate size equipment. Cat had some problems with their aluminum radiators. Lots of great info, recommend start by replacing thermostat and go from there but gauge accuracy could definitely be the issue.. Good Luck, Great Coach..

Agree that WRV was a quality coach builder but as they build their own chassis (Peak), they supplied the radiator package. The engine builders give minimum requirements but they don't provide the cooling equipment.

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Old 05-30-2015, 09:03 PM   #23
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Have you checked to make sure your fan is coming on high when you are overheating? I would disconnect the ground to your direct fan control and see if it goes to high speed.

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