Questions and Answers
Buick Freezing Up
Q. Maybe you can steer me in the right direction. I have a 1991 Buick Regal LE with a 3.8L V6 The problem began last spring. I have had it in & out of several shops no one is able to find the problem.
The problem occurs after the car has been driven approximately 30 miles with either the heater or the A/C on. If the heater is on, the heater quits heating. If the A/C is on, it quits cooling.
Last night my wife had the heater on, it stopped heating. When she got home, I was going to check the transmission fluid before I turned the engine off. I noticed that the lines going into the firewall back a cylinder object back to the lines coming out of the compressor were frozen as if the A/C had been on. There was about 1/8" of frost on these lines and components.
What do you think is the problem? Any help is appreciated.
TerylA. What is happening here is the evaporator core inside the heater box is freezing up. This usually happens when the Defrost or A/C controls are left on MAX for too long.
I suspect you have Automatic Climate Control in that car. The ACC uses a combination of A/C and heat to maintain the set temperature inside the car. If you have the Recirculate mode on for too long, the evaporator core will freeze up. The only way to prevent this is to take it off recirculate every 15 or 20 minutes and the incoming air will melt the ice and normal operation will resume.
