1997 Buick Park Avenue

IS the problem that you are not getting heat? Keep in mind that the compressor should kick on when the defroster is on.

Let me know.

Joe

I need you to check something for me. First, make sure the engine is warming up to normal operating temp. Then, with the engine running, hot, and the heater on high, feel both heater core hoses to see if they are both hot. IF they are, then there is a problem with the blend door. It is a vent door that determines if you get heat or AC in the car. If it doesn't switch, even if the heater core is 200 degrees, you won't get heat.

Let me know what you find. As far as the compressor coming on, you should still get heat.

What you need to do is remove the hoses and see if you can flush the heater core. Force water both directions using the pressure from a garden hose. THat should clean it out. If it doesn't and you can't get water through it, then it will most likely need replaced.

Let me know what you find or if you have other questions.

Take care,
Joe

The only other thing I can think of is a plugged radiator or a radiator hose is collapsing and not allowing flow. Does the engine temp heat up and cool down quickly?

If you start the engine with the engine cold, as it warms and the thermostat opens, do you see the coolant circulate?