On a recent trip the cooling fan fell of my Cat 3126b motor. There was no damage other than to the fan. I had a diesel shop put a new fan on. On my way home (80 miles from the shop, the coach heated up and the check engine light came on. I pulled over and let the coach idle for a while and the light went off. I then changed both thermostats thinking that the high temp that was caused when the fan fell of might have affect the thermostat performance.
After completing this task I took the coach for a run for about 30 miles where there was a somewhat steep grade. The coach overheated and the check engine light went on briefly then off...outside temp was around 89-90 degrees F. The coach cooled somewhat back to home but maintained a temp about 195-200 (thermostats are 190). The fan blade is the same as the one that came off. Mechanic doesn't know what is going on.
He suggested that the high temp that resulted when fan came off could have affected the water pump saying the high temP could cause the impeller to expand on the shaft, and cooling it off would engage it again but if it gets up to temp it might slip. My question is has anyone ever heard of this happening to a water pump?
Any other suggestions of what might cause the overheating would be appreciated....in 4 years I have never had any overheating problems, steep grades in Idaho, hot day pulling toad, etc.
2000 Cat 3126B engine, Magnum chassis, Allison 6 speed trans, coach was made by Harney, now has 38,000 miles.
Thanks for any help.....