Hey, I have a 2006 mercury montego with 65,000 miles. Car only blows cold air when giving gas (even stopped). The pressure on the low side is off the charts when idling but drops to about 35/40 when giving gas. Brought it to a mechanic he changed the expansion valve, no improvement, I added more refrigerant no improvement. To my untrained eye looks like compressor is engaged even when idling. What do you think it could be?
Thanks
So after much research it seems that the compressor control valve often goes bad on these cars. I changed it and pressures are now good when idling and it's blowing 48 degrees. Hope this may help someone in the future
Great job, thanks for letting us know!
Go to a competent mechanic who actually knows what he's doing. Air conditioners only work within a very tight (only + or - an ounce will not work right) tolerances. It can be dangerous. You also put air in the system, which isn't supposed to be there.
