This is an unusal problem I have never come accross before. I own a 1995 Dodge Neon sport coupe, 2 door, with the 1.9 Ltr. DOHC eng. with power bulge hood. With the engine running at idle, both cooling fans run normally and keep the engine at normal temp. While running the vehicle in stop and go traffic, the cooling system keeps the engine at normal operating temp. however when running the vehicle on the highway, the engine temp will climb, the overheat alarm sounds, and the engine soon overheats. Turning on the interior heater fan will help cool the engine down and maintain cooler operating temperature, however, driving with the heat turned on and the windows rolled down is not how I like to drive in the summer. Has anyone ever experienced this problem before? Any help would be appreicated.