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ISX15 help needed - Printable Version

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ISX15 help needed - 4eye4valve - 03-07-2022

Hello,
New member here trying to find help on a new to me truck.
Ive been reading and trying to find answers and feel like its tine to make a post asking for help.
I have a 2011 KW T660 with an ISX15 engine. The whole truck was neglected from previous owners and now im doing my best to fix everything.
The very first thing i need is someone to look at the pcm tuning so i can make sure no further damage occurs. It was deleted and tuned a couple of years ago in Memphis. I dont think it was done correctly. I purchased an Inline 6 and just got it in. I just need to get insite now so i can pull up the programming to look at.
One of the first issues i need to adress is that the fan runs way too much and at very unusual times. Ive replaced all of the ac switches, fan clutch solenoid, etc, but no change. It runs more often below 37 degrees. And nearly works properly when its hotter outside, but still runs too much. Sometimes for hours at a time.
Although i have several issues to ask for help with, im going to keep it to one at a time.
Once the tune is sorted, then i can comfortably move on to the rest.
Thanks in advance for any help.

Rick


RE: ISX15 help needed - hookliftpete - 03-07-2022

Aside from likely other issues, the air line to the fan could be badly leaking which would cause the fan clutch to stay engaged excessively.


RE: ISX15 help needed - Rawze - 03-07-2022

(03-07-2022 )4eye4valve Wrote:  ...
fan runs way too much and at very unusual times.
...
It runs more often below 37 degrees.
And nearly works properly when its hotter outside, but still runs too much. Sometimes for hours at a time.

Rick


(cold weather and fan clutch)...
The fan is supposed to run when its freezing outside (to reduce A/C refrigerant pressure) because the A/C is working its arsse off to reduce humidity in the cab, due to the "defrost" / heater on the windshield being active. SO your first complaint is not a complain but you not understanding how the system works. - Personally, I tend to unplug the A/C compressor on my truck in winter times to prevent that crap... but that is just me.


(beaing on when it should not be)...

What needs to happen FIRST is to determine if the ecm/cab controller is "commanding" the fan on.. or if it is on when the computer(s) says it is "off". Until you determine this.. your wasting your time completely trying to determine what it is doing or what may be wrong.

If the fan is on for hours at a time, then look in the ecm (or cab controller) to see what triggered it. Otherwise you will guess until your blue in the face. At the very least, it needs to be determined if the actual fan state matches what the ecm/cab controller actually wants. It is completely pointless to throw parts at it if the thing is being told to be on and it is simply doing what is being requested of it.

Also, if someone has adjusted the "fan on" temperature setting in the engine ecm too low then it will work harder, and more often too.

====

If it is "on" and the ecm/cab controller thinks it is actually "off" .. Then that leads someone towards sticky solenoids, air leaks, or perhaps the common issue of the clutch getting rusted up and hanging up when it rains a lot and the truck sits, etc.


RE: ISX15 help needed - 4eye4valve - 03-07-2022

(03-07-2022 )Rawze Wrote:  
(03-07-2022 )4eye4valve Wrote:  ...
fan runs way too much and at very unusual times.
...
It runs more often below 37 degrees.
And nearly works properly when its hotter outside, but still runs too much. Sometimes for hours at a time.

Rick


(cold weather and fan clutch)...
The fan is supposed to run when its freezing outside (to reduce A/C refrigerant pressure) because the A/C is working its arsse off to reduce humidity in the cab, due to the "defrost" / heater on the windshield being active. SO your first complaint is not a complain but you not understanding how the system works. - Personally, I tend to unplug the A/C compressor on my truck in winter times to prevent that crap... but that is just me.


(beaing on when it should not be)...

What needs to happen FIRST is to determine if the ecm/cab controller is "commanding" the fan on.. or if it is on when the computer(s) says it is "off". Until you determine this.. your wasting your time completely trying to determine what it is doing or what may be wrong.

If the fan is on for hours at a time, then look in the ecm (or cab controller) to see what triggered it. Otherwise you will guess until your blue in the face. At the very least, it needs to be determined if the actual fan state matches what the ecm/cab controller actually wants. It is completely pointless to throw parts at it if the thing is being told to be on and it is simply doing what is being requested of it.

Also, if someone has adjusted the "fan on" temperature setting in the engine ecm too low then it will work harder, and more often too.

====

If it is "on" and the ecm/cab controller thinks it is actually "off" .. Then that leads someone towards sticky solenoids, air leaks, or perhaps the common issue of the clutch getting rusted up and hanging up when it rains a lot and the truck sits, etc.


Thank you for the reply. I agree that ive been poking around in the dark trying to figure out the fan issue without knowing what is commanding it to run. That is why i have been reading on here and why i bought the inline 6 connectors. Im hoping that once i have an insite program, i can view what is commanding the fan to run. The fan does this whether or not the defrost, heat, ac is on or off. Those have had no bearing in changing the issue. When its not running on its own, i am able to turn it on and off via the dash mounted switch and it functions as intended.


RE: ISX15 help needed - Kw9006nz - 03-08-2022

The cm870 I had, had the orings inside the fan clutch go bad and it would stay on after start up until it got warm enough. On warm to hot days it would act normal and then out of no where it would come on for half a day then go back to normal and being controlled by the switch normally. But below 45 degrees OAT it was a crap shoot on its behavior. I unplugged my a/c compressor and my fan clutch air supply solenoid and adding an aux switch the the solenoid so I could activate it with the key off and thats when I heard the air leak. New fan clutch and bingo bango down the road I went