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Discussion Starter #1
A/C is out. Added freon, but didn't help. Now the fan is always running. I'm lost at this point. Please help.
 

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Go ahead, blame me. Everybody does 馃檮
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How's the coolant level?
 

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'05 CTS-V
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Moved from the '16+ CTS-V forum to the '08-13 CTS forum. Hopefully your fellow CTS owners can help you out.
 

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2011 CTS Coupe FE3, 2003 Thunderbird, Gone 2013 ATS, 02 Deville
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first thing is to get some A/C gauges form a parts store on loan (no charge) and take some readings. then get back to us.
 

2011 CTS Coupe Premium
Orlando - We take orphans
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Since you added Freon first thing I'd do is to remove the negative battery cable for about five minutes. Once the AC on a GM car trips out it needs a hard reset before the compressor will turn on. A really good scan tool should also reset but have seen no sign that one is present.
 

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Did you KNOW it was low on refrigerant or just add it on a hunch?
Too much in the system is also no bueno.

I would verify proper coolant level and check refrigerant levels for starters.
 

2011 CTS Coupe Premium
Orlando - We take orphans
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Agree, too much Freon is as bad as too little (and will often pop the pressure relief valve). At a minimum you need to know the low side pressure at 2000 rpm, high fan and with a blower in front to the car. The "sweet spot" at 90f is 25 to 35 psi. 40 is OK but when it drops under 20, it should begin cycling and not be as cool. Low Freon will also cause hoses and the dryer to ice up.
If the compressor is not running, the static pressure is around 90 psi. Under 50 and the compressor may never kick in (and will usually display a warning).
Point is that it is critical to monitor at least the low pressure but if not working then is best to also monitor the high pressure (why good gauges have two dials). A blocked oriface tube or expansion valve can make the pressure skyrocket.
 

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Discussion Starter #9
I'm in Houston and it's STUPID hot! Need answers fast.

Charged the ac... Runs cold for a few minutes..then hot. Sometimes it will run cold for a few hours.

Fan is working. Compressor is kicking on.

I do have high pressure and when I release some... It will lock on cold for awhile.

Any info will be helpful!
 

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I'm in Houston and it's STUPID hot! Need answers fast.

Charged the ac... Runs cold for a few minutes..then hot. Sometimes it will run cold for a few hours.

Fan is working. Compressor is kicking on.

I do have high pressure and when I release some... It will lock on cold for awhile.

Any info will be helpful!
It's not necessary to begin another thread for the same problem, especially when you're posting in the wrong subforum...
 

Super Moderator
'05 CTS-V
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Moved from the '16+ CTS-V forum to the '08-13 CTS forum. Hopefully your fellow CTS owners can help you out.
9 months later and you apparently still think your 2011 CTS is a 2016+ CTS-V. That is still not correct, so I merged your latest thread into the one I moved to the correct forum 9 months ago. (Thanks for finding the link, @Long.)


Charged the ac... Runs cold for a few minutes..then hot. Sometimes it will run cold for a few hours.

Fan is working. Compressor is kicking on.

I do have high pressure and when I release some... It will lock on cold for awhile.
To properly diagnose what's going on with the A/C system you need to know the high and low system pressures, outside temperature, and the temperature coming out of the vents. Harbor Freight sells an affordable gauge manifold set that will allow you to see what the system pressures are doing. Blindly charging freon (that may not have been needed) or releasing it isn't going to help you figure out why the A/C isn't working all the time.
 

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2005 Base CTS work at Pullen solenoids Glass Factory for 36 and a half years
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Google "Scotty Kilmer air conditioning" and you will come up with some of his YouTube videos about air conditioning systems. Watch some of them and you may get some ideas that will help you.

Roy
 

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Discussion Starter #14
Thanks everyone....
And I know I don't own a V. But thanks for moving it to the right spot.

Going to grab a set of gauges in the morning to see what comes up and post back with answers. Had a few people tell me to check the pressure sensor... Another says it might be the expansion valve. Sewell Cadillac here in Houston actually said that some of the parts are not available anymore and he would suggest me taking it a a smaller shop. I find that very odd.:unsure:
 

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2009 CTS 3.6L DI rebuilt to FE3 J55 G80 3.42:1
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Thanks everyone....
And I know I don't own a V. But thanks for moving it to the right spot.

Going to grab a set of gauges in the morning to see what comes up and post back with answers. Had a few people tell me to check the pressure sensor... Another says it might be the expansion valve. Sewell Cadillac here in Houston actually said that some of the parts are not available anymore and he would suggest me taking it a a smaller shop. I find that very odd.:unsure:
There are shops that are expert in AC repair, hence the dealer's suggestion. If you're not an expert and don't have the equipment this may be a case where it makes a lot of sense to utilize a pro. Are you aware that air must be pumped out of the system if it is opened to replace any components? An expensive piece of equipment beyond the gauge set.
 

2011 CTS Coupe Premium
Orlando - We take orphans
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"Runs cold for a few minutes..then hot. Sometimes it will run cold for a few hours. " if pressures are right then may have a diverter problem. There is a servo that moves the hot/cold flapper and they often stick.

I can tell a lot with just one of these. Have seen someone use the compressor to pull a vaccuum but have a two stage pump that can get down under 75 microns. Like to see it hold a vaccuum overnight before charging. Was under $200.00
 

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'05 CTS-V
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Are you aware that air must be pumped out of the system if it is opened to replace any components? An expensive piece of equipment beyond the gauge set.
The vacuum pump isn't that expensive - $90 at Harbor Freight, minus whatever of their ever-present sales or discounts is available. That's where I got my gauge manifold set, too.
 

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2011 CTS Coupe FE3, 2003 Thunderbird, Gone 2013 ATS, 02 Deville
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most of the auto parts stores have loan a tool, so there is no cost for a good set of AC gauges or vacuum pump.
 
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