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Topic: 2004 U320 ISM doesn't warm up (Read 2531 times) previous topic - next topic

Re: 2004 U320 ISM doesn't warm up

Reply #25 –
Quote from: dsd –
So do you still have the IAT temp input? I have noticed that under odd circumstances you can exceed IAT and having it being monitored is a good thing.
Yup. Its reading IAT from the original sensor for the fan controller as well as the coolant temperature. The transmission is broadcasting the retarder temperature out, so I added that in as well. It was pretty cool to watch it when the engine was still cold and the IAT was driving the fan command.
1991 U300 Side Aisle 6V92 Silver #3897
2004 U320 40' #6246

Re: 2004 U320 ISM doesn't warm up

Reply #26 –
Quote from: Jan & Richard –
So for a Cummins M-11/ISM, what is the acceptable temperature range.  Input Air Temperature is one of the parameters that I monitor but I have never seen posted what that temperature should be.  I generally see an IAT of about 20 degrees above ambient air temperature.
There are two temperatures that cummins sometimes shares. Inlet air temperature is measured just after the air filter. They sometimes refer to this as turbo inlet temperature.  The other temperature is intake manifold temperature.  This is after the turbo and CAC. I can't remember the upper limit for the intake manifold temperature. But cummins would test our machines before we were allowed to sell the machines. The cooling system needed to keep the intake temperature and coolant temperature under their limits in 120deg F ambient temperature.  And they really preferred that to be a higher number. 
1991 U300 Side Aisle 6V92 Silver #3897
2004 U320 40' #6246

Re: 2004 U320 ISM doesn't warm up

Reply #27 –
Quote from: Jan & Richard –
So for a Cummins M-11/ISM, what is the acceptable temperature range.  Input Air Temperature is one of the parameters that I monitor but I have never seen posted what that temperature should be.  I generally see an IAT of about 20 degrees above ambient air temperature.
So 15-20 degrees is a good number. The electronic does as have a preselected number but I dont recall what it was. The wax valve has a background minimum speed adjustment that is factory set at like 20% all the time. This would eliminate any hi IAT possibility. The only time I see it is when i have gone down a long decent then transition into a hard climb. The IAT will peak upon the request of hi power with little fan speed. I also should disclose that I have my background speed set nearly as low as possible. They do turn while operating but do little work. I really want to monitor my fan speeds so I could find a good background speed. If I have say a 300rpm demand at flat freeway speed I would make that the speed. This is seeking better fuel economy. No need to run higher than needed. This is why when transitioning down hill to up hill there is a delay in my fan speeds to temperature. I have installed a secondary temperature bulb in my inlet that will drive the fans to hi during this event then typically there has been enough heat added to get past the IAT poor control area. I definitely would of preferred the possibility for a better controller, were all this could of been incorporated. Im happy with what I have but a better electronic controller would be the way to go IMO. I also added a Hi fan select for anytime the retarder is in operation. Putting a 1 minute delay off timer would be nice. Be fine for them to run after retarder use. Because I had drove with a bad controller with fans on Hi all the time I realized one huge benefit to this also. Cooler sleeping area. I incorporated a manual switch to turn the fans on HI. I regularly use this on long descents ( no timer) and always try to remember to use a 1/2 hour before stopping to strip all the extra heat out of the radiator, engine and transmission. It will loose 20 degrees engine and transmission. All the radiator heat. Huge difference.

Re: 2004 U320 ISM doesn't warm up

Reply #28 –
Quote from: kgrover –
Coolant temp and Intake temps have been right where they should be for the whole trip.

Ken, what do you consider to be "right where they should be"?  180 degrees?  Where are you reading coolant temp?  From your Bluefire?
George Mann
2002 U320 #5934
2017 Rubicon
2013 BMW GS
Waterford MI

Re: 2004 U320 ISM doesn't warm up

Reply #29 –
The below numbers and chart are from the Cummins troubleshooting manual.
I have the fan set to start ramping up at 195°F and it's on full by 203°F. That's a little bit lower then Cummins spec, but works well. On the trip back from Mexico, she was at full throttle for about 20 minutes straight climbing some grades and the engine temp held at 200°F.

The bluefire is reading the coolant temp from the Cummins ECM. I can also see the coolant temp and intake temp from the fan controller sensors. They are in a different location that the engine sensors. If I could get someone from Bluefire to give me the list of messages they are reading, I could add more information to that screen, but I've had no luck so far.

The chart shows some data from early testing. The blue line is the sensor the fan controller is reading. The green line is what the engine ECM is reporting.  The Engine reads the temperature at the thermostat housing. The fan controller sensor is in the side of the block towards the rear of the engine. I've tweaked the settings since this graph. I was adjusting as we were driving out to Mexico. My buddy was driving, not me.

Code: [Select]
Cooling System
Coolant Capacity (engine only) ............ ,..................................................................................... 9.5 liters [10 qt]
Standard Modulating Thermostat Range .................................................................... 82 to 93°C [180 to 200°F]
Cylinder Block Coolant Pressure (pressure cap removed):
Minimum
Closed Thermostat - 1800 rpm - No Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 kPa [20 psi]
Maximum
Closed Thermostat ... 275 kPa [40 psi]
Maximum Allowable Operating Coolant Temperature ...................................................................... 100°C [212°F]
Minimum Recommended Operating Coolant Temperature ................................................................ 70°C [160°F]
Minimum Recommended Pressure Cap .......................................................................................... 48 kPa [7 psi]
Maximum Allowable Coolant Flow to Accessories (liters/minute [gpm]) ................................... 75.7 Liters [20 gal]
Coolant Sensing Fan Control:
On ... 96°C [205°F]
Off ... 91°C [195°F]

1991 U300 Side Aisle 6V92 Silver #3897
2004 U320 40' #6246

Re: 2004 U320 ISM doesn't warm up

Reply #30 –
Very good information and thanks for providing.  So the manual says the t-stat should modulate from 180-200F, the minimum and maximum coolant temps are 160F and 212F, and the fan controller should be on at 205F and off at 195F.
Is the Sauer Danfoss controller adjustable?  Fan on at 205 seems really high if you don't expect the coolant to get over 212.
I feel better knowing that it's OK to run the engine as low as 160 but I will study my problem some more to try to determine if my thermostat is stuck open or my fan just comes on too low.  If the Sauer Danfoss control is adjustable, hopefully someone can provide some instruction.

Thanks!
George Mann
2002 U320 #5934
2017 Rubicon
2013 BMW GS
Waterford MI

Re: 2004 U320 ISM doesn't warm up

Reply #31 –
Hi George,

My electronic fan controller failed and I asked FOT for information, they sent me these two technical bulletins. The parameter setup instruction start on page 23, some special equipment is required.

I hope this helps you.

Bob Carbone
Grand Cane, LA

Bob & Suzy
2000 U320 4010 SPEC
2006 Honda CRV