I pulled a Cummins with a goose neck loaded down 30 miles at 70MPH. Well 15 miles in to it I smelt coolant and my temps shot up. I pulled over, changed from Extreme race, to tow agg and got back on the road. No more problems. Then I got on the dyno and played around. Not bad for one day of work. Anyhow now occasionally when I smash the pedal it spits coolant out underneath while im going down the road. Not all the time but some times. Does the same thing when I am pulling my 40ft horse trailer and have to hammer down. I think I read some where that was the EGR crap? Any help guys? Im lost on this one.