I found the one I was driving really liked to be shifted down low, real low and give it extra time for the RPMs to drop.
I had the exact same problem with our ISX 600....got a reflash and it feels just like an old Cat now.
Thanks HeavyD in the process of purchasing this truck and trying to get ahead of any problems, can Intl give me a sensor location for this engine. I am a
Truck has been in service for 3 years. Engine still has warranty. Engine has the big warranty on it, but it is a custom warranty with Thom's Transport and may not transfer ownership if it is sold. Truck hasn't been scanned in over a year. ECM calibration is out of date and has one open recall for the linear power module for the blower motor. Looks like the EGR cooler was done about 2 years ago.