1984 Pontiac Trans Am v8 5.0 305 mileage: 77,000. I have an '84 Trans Am, I put new manual transmission, new carburetor, new thermostat and Radiator with hoses. When I drive, I feel heat coming in where the stick shift knob is, on the instrument panel, I have radiator arrow coming from 220 to 240, and then it climbs over. What is a possible cause for such a thing? What can you tell me where to look? No leaks.
First check the radiator temperature with a separate temperature gauge. This will double-check your dash gauge. Remove the thermostat and test in a pan of hot water. It may be faulty. Check for exhaust in the cooling system. (Blown Head Gasket).