No heat 2006 Nissan Frontier XE 4.0 Cylinder
Heat is not warming up as much as it should. Water hose going in feels hot
to the touch. The outflow line is cool. It heats and goes cold and on one
occasion after I parked it went cold and stayed cold. Went out and started
truck again and let it warm up and it heated some, but it's only about half as
warm as it should be. The heat level fluctuated while driving down the
highway. Coolant levels are good. No signs of overheating.