Air Conditioning Acting Up

[Cardassian]

The air on my 96 Camry V6 has caused a lot of problems. I think it is no longer leaking and the evaporator, expansion valve, and receiver drier have been replaced. It cycles on and off very quickly, about every 4 seconds during idle. Coming out of the garage it cools very well. However after parking in the sun it never does any cooling. Also it is quite noisy and seems to put an excessive load on the engine. Next morning it works fine again out of the garage. I plan to trade it very soon but I would like to know what the problem is.

[toyomoho]

Did you evacuate the system before recharging with Freon? If not, moisture could still be in the system that can freeze. This will cause the A/C to fail to cool and possibly damage the compressor. Was the system completely charged with Freon?

[Cardassian]

The work was done by a mechanic that I have dealt with for many years, so I think it was done properly with the proper equipment.

[OEMonkey]

It's normal. A basic understanding of pressure differential, and the effects of pressure and temp. helps.
Basically the refrigerant is used to cool the interior of the car by first absorbing heat from the interior and dissipates it to the cooler outside air. Low side press. & temp. are kept low to absorb heat, High side press. & temp. are kept high to dissipate heat. So, the refrigerant is not actually blowing cold air in the cabin but absorbing the heat inside of it. Removing the heat actually cools the interior. Remember that the heat from something hot always moves to something colder. Now you know why it takes longer to cool a vehicle that's been sitting under the sun.

For peace of mind, you can always take it back to your trusted mechanic. a/c dye is normally put in every time the system is charged. See if they can find a leak. Or they can check for dirty/blocked condenser fins, refrigerant level, and see if it holds vac. for at least 5 mins. good luck, hth.

[Cardassian]

Thanks for the lesson and the suggestions OEMonkey. It does not cool at all after the first time out of the garage. I stopped by the garage yesterday and the mechanic said it is out of refrigerant again. I expect to trade it in soon so I don't plan any more work on it for now.