Quote Originally Posted by quickdodgeŽ
If I sit at idle at a red light or something or having the car running in a parking lot, my car's heater blows out cool air. When I am accelerating, it heats back up to hot air. I know this is probably some simple answer, I just don't know it. Can anyone offer up cause/fix? It's a Buick with 3100 engine in it. Thanks. Later, QD.
Check for leaks first and top off fluid. On those 3100's, if it's had a leak or had a cooling system fix and it's not bled properly, there will be an air pocket trapped. Some of the 3100 have a bleeder screw on both the water pump outlet housing and on the thermostat housing. The best thing to do is to crank it up and let it warm up. When the needle starts to get towards the center, cut the car off and open the bleeder screw. It should stream out in a rather smooth fashion. If it sputters out, there was an air pocket. The bleeder screw is gonna be a 7mm and don't take alot of torque to tighten down. Just snug it and keep going. Let me know if that helps.