Fan stuck (Cummins isx)

Another thing to look out for unrelated is the DEF. DEF will separate and may even solidify in the tank causing other issues.

 

You have been given some bad info. DEF does not separate and I have never seen it solidify unless it was contaminated with another substance. Even if it freezes (which is normal btw) once thawed it returns to its original state.

https://www.cumminsfiltration.com/sites/default/files/MB10033.pdf

 

Happy to be corrected on this.

 

No AC works fine, nothing done to it.

My Jake brake has started whistling though. Sound is like that of a bad fan belt. Not getting better or worse, only when I activate it.

I'm heading home tomorrow, be their Tuesday. I'll have to see what wrench says.

I try to get everything done at home when possible.

 

I have the dreaded Cummins ISX with EGR (circa 2006). I also had incessant fan clutch engaging.

Two days ago I stopped to fuel and turned off the engine. When I tried to start the engine again I got the sound of the starter engaging and that was it. As it turned out another driver from my company was fueling next to me. He pulled around facing back to the fuel island in front of a truck that had no driver in it. We started charging my batteries, thinking that was the issue.

After 30 minutes of him high idling I still couldn't start the engine. Then he watched the belts as I tried to start and saw that the air compressor for the air conditioner was not allowing the smaller belt to turn. We cut off the belt and I could start the engine easily.

Yesterday I drove to my mechanic. He replaced the air compressor (completely locked up), the belt tensioner, and the pulley. The old belt tensioner and the pulley were obviously not rolling smoothly, I could feel them grinding.

Today I drove the truck with perfectly functioning air conditioning and the fan clutch behaved properly. I had to engage the fan clutch manually while running dirt roads before and after a 10% grade. I used to have the fan on constantly in a situation like that.

My mechanic also replaced an electrical connection to the air compressor.