Have a 05 lly Kodiak that with egr delete truck runs normal temp running down the interstate at 70-75mph as soon as i start running over that the engine temp will peg out to 260 if i stay under the speeds it never over heats even when i have the plow on and loaded with the salt and my heater won't put out heat at idle unless i run high idle I'm thinking bad water pump impeller might be slipping on the shaft kind of at a loss thanks for any help
