Engine Temp Issue

[tomkat]

I just purchased a 2009 Phaeton QTH 40 with the Cummins ISC 360 engine. Driving the coach from where I purchased it in Phoenix to my home in Tucson, I became concerned about the temperature gauge. Without numbers on the gauge, just lines, I can't give actual temperatures, but here's what I saw. The needle would start at a point just above half on the gauge, which I assumed to be normal. However, on flat road with ambient temperatures at or around 90, the needle would creep up to just below the red line, then cycle back to it's starting point. I could hear the fan clutch kick in. It continued to do this for most of the 120 mile trip. At one point, I pulled over in a rest area to take a look. The engine did not seem to be hotter than normal.
After returning to the dealer for a thermostat change and coolant drain and fill, the same thing occurred again. Any ideas or similar situations? I'm just a little frustrated, but perhaps this is a normal occurrence.

[Rambeau]

Fan should have a temperature sensor ...either oil or water that engages/disengages the fan...sensor will be separate from the dash gauge sensor. Sound like it is calling for the fan at too high a temperature.

[no3putt]

Have you cleaned the radatior. Did ours and is running cooler. Easy to do yourself.

[Slice]

not normal My 08 same model engine the temp gauge pointer barley moves, I also back this up with the engine computer monitor that monitors it and it stays at 180 or 190 ish.. even climbing hills in arkansas.. I suspect dirty radiator ? rear radiators get dirty quickly...

[dpinvidic]

The LBCU (Three line alpha-numeric display) will display temperature.

Do you have one of these in your dash (I think they were available in 2009)?

Regards,

Dan

[Melmoses]

I have the same coach and I clean the radiator once a year since it is the rear radiator. Many people never clean theirs and that may well be your issue.

Get some Extreme Simple Green cleaner that is made for aluminum. Use a 2 gal spray and soak it good on both sides. To do the job right you have to open the engine access in the bedroom. To do that you first remove the panel that is on the bottom part of the left side of the closet under the mirror. Then you need to remove the access door on the floor which is held in place by screws that you can't see. The edge of mine hits the bottom edge of the bed. Use a screw driver to feel around for the screws in the carpet. Once you have the hatch open then you will see the backside of the top of the radiator and the CAC. Spray very good with the cleaner, let soak a few minutes.

I then take a long garden wand with a hose attached. Spray clean water from the rear, underneath reaching up to the rear of it and then haul it inside and spray from inside. After rinsing very well, I crank the engine and let it blow through the radiator. I repeat the cleaner, and the rinsing a couple of times. I do additional rinses as necessary until there are no bubbles when the engine fan is blowing through the radiator.

You would be surprised at what comes out of that radiator. Cleaning it solved my high temp issue.

[Melmoses]

One other thing I thought of. Can't remember if there are many hills/grades between Tucson and Phoenix but you should try to keep the rpms up around 1700 when climbing by downshifting if necessary. Still think it is the radiator.

[tomkat]

The radiator was thoroughly cleaned, front and back. I do have the in-dash display. Did not think of scrolling through that for engine temp. It is mostly flat between Tucson and Phoenix.

[MDB]

I experienced the same problem, there are two sensors that regulate the temperature, replaced both and problem solved.

[dpinvidic]

Originally Posted by MDB

I experienced the same problem, there are two sensors that regulate the temperature, replaced both and problem solved.

Can you provide more details. Was it the fan temp sensor (the one with wax in it)? Was the thermostat OK?

Thanks,

Dan

[MDB]

Actually mine has a cat motor, it has two thermostats electric, which on a thread on this forum explained the problem. Dealer I took it to tightened the belt, replaced thermostat, and flushed the radiator, after all this it still had the problem, I found thread and told them to replace the thermostats, so it was a long way around the problem. Working well now. Hope this apply's to your problem.

[KF5UMC]

I might I have missed it but when the engine starts to over heat, did you visually verify the engine fan was actually turning? Your baseball cap should nearly blow off when you stand behind a running diesel pusher. Also do you actually hear the clutch fan kick on and off or are you hearing the transmission cooling fan???

My engine over heating problem was due to a faulty clutch mounted on the diesel (350 hp Cummins) fan and once replaced solve the problem. Replacing the thermostat did not fix the problem. In my case, this is a known problem on several coaches. The problem starts to show up around 25,000 miles.

[golfdover]

Good morning,
Our Phaeton 2011 QSH temps seem high to me.
Using the column computer I watch the temps rise on even the slightest of grades.
Often engine temp goes to 210 to 212 then the fan turns on and it will lower
The transmission temps will go to 210. We have the Allison synthetic fluid.
It seems if outside temps are in the high 70's to mid 80's and experiencing moderate grades as we head west on I-40ste both temps stay in the low 200's.
It seems to me these temps are high, but I don't know.
I have made the run between Tucson and Phoenix several times, it is relatively flat, some long grades, and have experienced the same temps as I mentioned above.

[ernieh]

The cycling is not unusual in hot weather, but hitting the red line before the fan kicks in is not.