A/C Testing

Just a quick walk through and reminder of A/C system testing. The complaint on the 2006 Sonata was the A/C was not cold. Checking the settings, they were fine for testing. You want the system set to coldest temp, a low blower speed and recirc (max) airflow. Put a thermometer in the center dash vent and look for A/C output to at least be 50F. Depending on variables like how long the car has been sitting in the sun, how hot the outside temps are, and such. You might have to drive a bit to reach coldest vent temps but this particular car was getting down to 40F with no driving at all other than from the parking area to inside the shop.

I don't see a problem. That is certainly cold enough. A test drive would be in order to determine if the problem is related to conditions that happen while driving. But while the car is inside it would be a good time to check the actual refrigerant charge. The customer had mentioned adding refrigerant himself. Usually that involves one of the A/C charge kits sold over the counter at so many parts stores and box stores. One of the problems with using the kit is that you have no idea whether the system is properly charged either before or after you use it. Personally, I don't see the point then. But if we didn't spend money on something we'd all be wondering what to do with it right? Anyway.... I connect the recovery/recycle machine and open both gauges. I recovered 1lb 9oz of refrigerant. The system was overcharged by 6oz.   

With a proper charge and a road test the A/C still operated as designed. Could the overcharge have been the problem? Yes. More is not always better. The pressures would not be correct and could cause the compressor to cycle more often than designed. Or, there could be another problem lurking in the shadows that has not shown up while the car was here. I just advise the customer and we see how that goes. 

Thanks for reading 

Kenneth Hayes

G&G Auto Repair