@my 4.3 v-6 automatic w/ trailer pkg. Has always spit out a little coolant enought to add a little every month or two. I have a 4000 lb trailer now and when I pulled it about 20 miles for the first time it immediately rejected more coolant all at once as I was parking the trailer. It was ejecting out the overflow tube. I find no leaks anywhere. I watched the temp gauge the whole twenty miles and it stayed normal. It seems to me that I might want to replace the radiator cap first. If the radiator was stopped up wouldn't it be overheating and show on the gauge? The oil never drops and coolant is not getting into the oil. If you have any suggestions it would be very helpful.