2005 Buick La Crosse Repair Question
Buick La Crosse Coolant Problem
You could have a few different issues here. 1 could be the blend door is stuck (allows hot and cold air to be changed and is inside the dash) or 2 the valve which lets the warm water into your heater core could be broken. I would check the coolant valve first. There should be 2 coolant lines that go into the firewall that actuate the coolant flow into the heater core. There is a valve that is actuated by a cable or a motor and could be jammed or broken. It is in the engine bay up against the firewall or just on the other side of the firewall inside of the car running along one of the 2 coolant lines. You should be able to manually move the valve and see if that gives you heat.
Your heater core could be plugged but based on how new your car is I wouldn't bet on it.
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