I have a 1996 Buick Regal Custom with a V6 3800 engine and it is not heating. How hard is it going to replace the heater core. </span></font>
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</>How do you know it is the heater core? Usually when those go bad they put a fog on your windshield and have the sweet aroma of anitfreeze. Have you checked your antifreeze latley? If it is low your car will not make heat. </></></>Edited by: Vortec-6000

before you change ur core, id suggest taking both hoses off at the engine side and just run a garden hose through to flush it out.