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A/C funny sounds from Dash

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Old Jun 9, 2009 | 08:02 AM
  #1  
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A/C funny sounds from Dash

Ok I searched and searched but couldnt find anything.

Does anyone know what's making that funny wheezing/air leaking sound comming from my Dash only when I run the AC?

I was thinking of taking her to the shop but I know how costly AC service can get.
The AC works but not as cold as I would like.

Any help would be greatly appreciated.

Thanks
Hot in Orlando
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Old Jun 9, 2009 | 09:21 AM
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Mine does this also, there is a hissing noise near the glovebo after I switch it on.
It slowly dissapears if I keep the AC on.
I get the feeling the noise is getting worse and that the AC is becoming less effective.
The best fix would be to just tear the whole thing out but AC is quite nice to have in a car with a black, leather interior and relativly large windows.
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Old Jun 9, 2009 | 10:43 AM
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From: Bath, OH
You're probably just a bit low on Freon (it very slowly dissipates thru the hoses, etc. over the years even in a properly functioning system) - get it topped up and you should be good. Just make sure you use the same type Freon (R12, etc.) that is already in there.
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Old Jun 9, 2009 | 12:14 PM
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From: Orlando
Thanks Dave,
I'll take her in tomorrow for a flush and refill.

I thought I might have one of those bad Thermostatic sumthin or other switches since that odd sound was comming from the dash every so often.

Crossing my fingers

I'll post up the results of the A/C service

Thanks again

7zoom

p.s. luvinmy94rx7
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Old Jun 9, 2009 | 04:21 PM
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What you're most likely hearing is the liquid refrigerant entering the expansion valve and being allowed to expand into a gas. It is not abnormal to be able to hear this.

You can easily check to see if your car needs more refrigerant (if your system has R-12 in it) by turning on the A/C and then looking for bubbles in the sight glass. No bubbles == no refrigerant needed. If you have bubbles then it could indicate a number of different problems. NOTE: This only works with R-12. This method is not reliable for R-134a.
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Old Jun 10, 2009 | 10:20 AM
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From: Orlando
Thanks for clarifying the sound.
I just returned from my mechanic who confirmed my pressure was down.
He added on can of Free on and said it was back to proper pressure.
I felt the AC and it was nice and cold.

Cost $49 for the can of free on half an hour labor total $88.00.

$88 for cold air works for me.

Now just crossing my fingers and hoping I dont have a leak.

Thanks again for the tips.

7zoom
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Old Jun 10, 2009 | 05:01 PM
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From: Bath, OH
Originally Posted by 7zoom
...Now just crossing my fingers and hoping I dont have a leak.

Thanks again for the tips.

7zoom
You're welcome. This is typical of the normal situation, where the Freon dissipates gradually over a long time. You should be OK for another 10 years.

Dave
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Old Jun 10, 2009 | 08:39 PM
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Losing refrigerant slowly over time is typical of systems in older cars which had long runs of non-barrier hose and old school compressors with shaft seals that were expected to leak. The RX-7 has VERY little hose in the system (mainly hard aluminum lines), and it is barrier hose so it should leak virtually nothing. The compressor is of a modern design and, again, should leak virtually nothing around the shaft seal unless it has failed.

I suspect you have a leak, especially if your system was performing well last summer. If it needs a recharge next summer or before then find and fix the leak...your compressor will thank you for it.
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Old Jun 11, 2009 | 01:25 PM
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From: Orlando
JM1FD,

Thanks for the insight. I purchased the car about 6 months ago and even then the AC wasnt really cold. I will keep an eye on it and if it starts to get weak I'll certainly find and repair the leak.

Thx

7zoom
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