QuestionMy car initially started to blow slightly warmer air but still cool a buddy of min checked the freon it was in the operating range. then the a/c started making a hissing sound when the a/c would first start up but it was cooling like normal. then the a/c started blowing hot air as if the heater were on full blast, currently the ac blows slightly warmer than outside air temp reguardless of temp setting. i have not checked the high side pressure but the compressor is running. What should i check first? i live in florida and its going to get hot, but im getting ready to ship out to iraq this summer and dont want to dump a lot of money into this car for it to sit around while im over there. any help you can give would be greatly appreciated.
AnswerPhil,
I can understand not wanting to dump the money prior. I've done two trips over there myself. (Active Army-16 years)
It sounds as though the vaccuum line controlling your blend door may have a small leak in it. (Depending upon how loud the hissing noise you hear is) If it is a faint hiss, on startup and when your turning it off, this is nothing to worry about-that is just the pressures inside the lines adjusting.
But being that you are noticing a slightly warmer than ambient temperature difference coming through the vents... my bet is that as I said either your vaccuum line has a small leak and not allowing the blend door to fully close.
Other possibilities... The diaghram in your door actuator may be going bad not allowing it to close. Or you may even have a piece of foreign material blocking the door from fully closing. It could be many things. The most expensive of which would be the door actuator, and then you would be looking around 450 dollars all inclusive.
How it works.... Inside your blower box under the passenger dash is the heater core for your heat and your a/c evaporator. What separates these items is a door. When you select heat, the door completely closes off the evaporator and all of the air is routed through your heater core. Likewise, when you select cool, the door shuts off your heater core and all of the air gets routed through your evaporator. If your door is just a little open when you want cool, it will be allowing a bit of air to flow through your heater core and that will get mixed with the cool air from the evaporator, canceling out any cooling effects that should occur.
What controls this door is a vaccuum operated actuator. When the vaccuum is pulled on the line it rotates, moving with it the door. The colder you set the temperature the more vaccuum is applied, the more it turns. If you are losing the vacuum be it through the actuator or the line, naturally it won't turn quite as much, thereby not closing or opening the desired component.
I would have it looked at by a reputable a/c shop just to verify. To have them check it out it shouold run you no more than about 100 bucks. Will it hurt anything to let it sit? No. It may even allow the vaccuum line to deteriorate a bit more over the next year and make it much easier to diagnose.
Thanks for your question, I hope I was of at least a little help. If I can do anything further now or in the future, please do not hesitate to ask. If you found this response at all helpful, please remember to rate it. Thanks again, take care, good luck, and be safe.
