AC not cold
Thread Starter
AudiWorld Senior Member
Joined: Mar 2002
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From: Michigan
AC not cold
The pipe is frosty which tells me the compressor, etc is working yet the blowing air is only slightly cooler than the 89 degree outside air. I hooked up the freon recharge hose to the low side with a can of 134a but it didn't take hardly any at all. Can and valve metal parts did not get cold.
turning the temp up all the way to HI blew even hotter than outside air. Back to LO turned off the sauna and not so cold air. This tells me the temp control working
Econ off and on works as the fast fan goes and compressor goes off when on.
So how do I get the frosty cold felt at the pipe inside the car? Any thoughts?
turning the temp up all the way to HI blew even hotter than outside air. Back to LO turned off the sauna and not so cold air. This tells me the temp control working
Econ off and on works as the fast fan goes and compressor goes off when on.
So how do I get the frosty cold felt at the pipe inside the car? Any thoughts?
AudiWorld Super User
Joined: Sep 2003
Posts: 5,002
Likes: 129
From: Fremont, CA
The A8 ac works in a mysterious way, mine was the same, it wouldn't take any Freon because there's still Freon in the system. Evacuate to nothing and charge it with exact amount specified and it works perfectly since. Cold as ice when needed... 99F
Cheers,
Louis
Cheers,
Louis
Last edited by ltooz_a6_a8_q7; Jun 30, 2018 at 02:49 PM.
AudiWorld Senior Member
Joined: Mar 2014
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From: Houston Texas
Check the low side pressure. Should be 35 psi or a little higher. If too low or too high 50 psi it will not work properly.
Most garages have the machine to evacuate and fill with proper amount. But the pressure gauge can tell you if there is another reason for not cooling.
Most garages have the machine to evacuate and fill with proper amount. But the pressure gauge can tell you if there is another reason for not cooling.
AudiWorld Super User
Joined: Jul 2001
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From: Wilbur by the Sea
I bet that the Schrader valve was not depressed while you are trying to charge it. Sometimes you will have to push down on your charge hose in order to get the Schrader valve open while you're charging it. I would try it again
Thread Starter
AudiWorld Senior Member
Joined: Mar 2002
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From: Michigan
Additional information: When i said the pipe was frosty, it is the high side, not the low side. I spoke to a friend at church today and going to have him put a gauge manifold on so I can see pressure on both sides. He said this was an indication of blockage. It still might require evacuating but he's going to tell me for sure tomorrow.
AudiWorld Super User
Joined: Oct 2001
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From: SF Bay Area, CA
FWIW, almost all A/C issues on the board over the years have ben resolved by proper evacuation and refilling by weight. Let the pro's do it. I do. Any A/C place or mechanic with the shop equipment can do it; nothing special about Audi's. The seemed-like-a-good-idea-at-the-time can stuff is a way to blow the compressor over time, which could cost about 100x what the can did, problem fixed or not. Other issue seen on the board sometimes is the high side pressure switch, but doesn't seem to play into it here.
Last edited by MP4.2+6.0; Jul 1, 2018 at 09:51 AM.
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Thread Starter
AudiWorld Senior Member
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From: Michigan
My friend is an AC / heat specialist with all the equipment. This was fortunate for our church members. On Friday, he fixed one of the church's AC systems which made it cool in the main sanctuary and congregation did not sweat. He is a retired heating and cooling guy.
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AudiWorld Wiseguy
Joined: Aug 2012
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From: Chicago
A8 has a variable capacity AC compressor so just hooking up pressure gauges won’t tell you the full story. And then trying to eyeball a fix with a can of r134a is generally an exercise in futility, with the grand prize being a blown compressor.
I can’t think of any instance like this over the years on the board where there wasn’t a part failure that the fix wasn’t ultimately a proper evacuation and recharge with the correct weight (600g) of refrigerant.
I can’t think of any instance like this over the years on the board where there wasn’t a part failure that the fix wasn’t ultimately a proper evacuation and recharge with the correct weight (600g) of refrigerant.
AudiWorld Super User
Joined: Mar 2015
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From: California
Trust the people here, unless your friend from church has the equipment to evacuate the system and then refill it with the proper weight, he won't be able to help you. You can look at pressures all day, but it can't help you diagnose anything on this car in particular.