1995 Camry AC Problem


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Old 05-14-09, 03:48 PM
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1995 Camry AC Problem

My 95 camry AC system has been working perfectly til now. Depending on how hot it is outside will determine how long my AC cooling will run. With temps in the 60s, cool air will blow for about 30 min and in the 70s about 15 min. No 80 deg temps yet.

I had a local shop charge it with freon with dye but it did not fix it. Now, I hear a vibrating noise once every 8 sec when the AC is running. What is that? The noise stops when I turn off the AC. I brought it back to the shop and they could not find traces of the dye. They said that I now need to replace the expansion valve and evaporator. I'm afraid to do that and it still does not fix my problem.

With the car engine off, I did notice the high pressure reading was high and the low pressure was low with the gauges connected. What does that mean?

If there is a restriction, then why do I get more cool air in cooler temps. What does outside temps have to do with the length of time my cool air blows and its relation to the expansion valve and evaporator?
 
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Old 05-14-09, 04:28 PM
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Originally Posted by MikeyBoy
With the car engine off, I did notice the high pressure reading was high and the low pressure was low with the gauges connected. What does that mean?

Absolutely Nothing... The only accurate readings that can be made are with the system running. The pressure should be equal with the system turned off, but the fact that it isnt doesnt really tell you anything.....

Why both expansion and evaporator????

An expansion valve will fail in 3 different ways...it will leak, it will stick open or stick shut.

Stuck open, the hi and low pressures are equalized, stuck shut, the high side SCREAMS, (Anything over 325 is extremely dangerous), but the low side pulls excessively low. The Expansion valve in some cases is dependant upon "AMBIENT" temperatures to determine flow rate.

Another thought would be a restricted condenser, or rather Blockage of airflow through it. If it cant dissipate heat, the heat is trapped and transferred back to the car....

Did you recently install a CAR -BRA....Change a radiator, or clean the leaves out of your Grille????
 
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Old 05-14-09, 05:14 PM
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I agree with what Uncle is saying, i would also throw in that about the only thing the evap can do is LEAK, if they have "sniffed" the system, including the evap drains, and there is no red dye running out of the evap drains (or compressor oil) that the evap is NOT leaking, this is a very costly thing to replace on most cars, dash has to be removed. Do you really trust this shop??
Gilly
 
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Old 05-14-09, 08:12 PM
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I did not recently change the radiator or clean leaves out of the grille. Why do you ask?

Any explanation of the vibrating noise once every 8 sec when the AC is running? This started after the recent freon charge.

If there is a restriction, then why do I get longer cool air in cooler outside temps?

How do you fix a restricted condenser or a blockage of airflow?

I have some trust in this shop but its more a friend of my dads.
 
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Old 05-15-09, 03:33 PM
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Originally Posted by MikeyBoy
I did not recently change the radiator or clean leaves out of the grille. Why do you ask?

Any explanation of the vibrating noise once every 8 sec when the AC is running? This started after the recent freon charge.

If there is a restriction, then why do I get longer cool air in cooler outside temps?

How do you fix a restricted condenser or a blockage of airflow?

.
The vibrating is the compressor cycling on and off. When the compressor engages, there is a huge DRAG, and a momentery lapse before the engine speed can catch up. Not really as much of an ISSUE as "Why is the compressor Cycling"?

Why I ask????........ and "How do you fix blocked airflow"?
Simple.......Bugs, leaves, road dirt, or even "Car wash" soap residue, can clog the "FINS" of a condenser, reducing the amount of airflow that can pass thru it..

The time frame that you have cold air.......As temperatures rise, so does the pressure in the system. Regardless of what or where the restriction is, the more temperature that is produced , the higher the pressure will be.

A very simple theory,,, Your air conditioner does nothing more than remove heat from the interior, and dump it outside..... The easier it is to DUMP..(Lower Ambient Temp) the more heat it can remove.

What We really need is for you to post the "OPERATING" gauge readings, before speculating on a cause.
 
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Old 06-03-09, 08:39 AM
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I had Aamco look at the AC since it was free and they told me that the AC has very little freon and no traces of any dye. They said it might be possible the previous car shop did not recharge it properly or put the proper dye. Now I'm confused if the previous shop even put any freon or dye in the system. If they did and there is no freon again then it must have leaked somewhere and they should be able to see some traces of the dye. I'm so lost. Please help!!!
 
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Old 06-03-09, 06:00 PM
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Possibly ask the local Toyota dealer what typically fails in the AC system. Explain the predicament to them, maybe it will ring a bell with them as far as an undetected freon leak. I am also guessing that it's the evaporator as you can't really SEE the evaporator until you've removed it from the car. Although if they added more AC oil, you should see the AC oil leaking out of the evap drains at least a little bit.
Gilly
 
 

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