# Does my A/C need service?



## sleepindirty (Mar 31, 2010)

when I first bought the car a few months ago the AC always seemed to blow icy cold, now not so much.
i live in north Texas, and i know that when the heat lays in, the auto a/c in most cars fall apart. 
but here are the facts!
when it gets 90 plus outside my ac doesn’t do much past jack. if i stay on the freeway and the rpm's stay in the 2kish range it cools, not great but livable.
if im on back streets, red lights, or getting on it, it blows hot air.
i brought it ot a local garage and he hooked up his gages to it and imeadetly told me that it has a good charge on it. he had me sit in the car and put 1200 rpm on the motor and let it go back to idle .. he then asked me to do it again and hold it there for a min. we let the car sit at idle for a bit ... then he had me go to 1200 again and we sat there for probably 1.5 mins. 
he tells me that there is a problem and he thinks its the compressor (says at 1200 rps its not pulling down?) but he wants me to leave the car with him for a few days while he makes some calls.. (my first warning sign). i told him that isn’t a problem that i have a warranty on the car and any sae mechanic can do the repairs. he tell me that he isn’t sae certified.. if im looking for warranty work ide have to take it to a place down the street (cool air) and they can do warranty work. i go there and they will look at the car and tell me if something is wrong .. but it will be a 40 dollar fee for the check up. this seems absurd to me.. if something is wrong they can fix it and make some money .. but making me pay to find out if there is a problem seems crazy :willy:


what do you guys think. should i just pony up the 40 bucks? or is this normal for our cars A/C?

oh ya .. i want to get this fixed before we go to kansas for the GTO convention... dont think i can stand to drive from texas to kansas with a petering A/C


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## Mike_V (Mar 10, 2006)

My A/C is too cold - no matter what I'm doing or how hot it is. It can be 90+ out and I can never leave it on full cold 'blue area'. I've heard a lot of people complain that their A/C is not cold enough, so it seems to be hit or miss with the GTO.

I know a lot of places are doing this diagnostic fee crap now, but screw that.


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## GTO JUDGE (May 14, 2005)

My AC works fine. You must have an aftermarket warranty? My GMPP covers the AC compressor. 
He must have it a few days while he makes some calls? Who's he going to call and it will take days to do it? 

I know a lot of guys shy away from the dealer's service many view them as evil and gouging. Many have had bad experiences with them and they have their reasons for not patronizing them (understandable). I know in my area many shops labor charges are close to the same as what dealers charge for service. Many, MANY years ago service charges at a dealer were MUCH higher than those of a corner shop. 

My point... for about the same or a few dollars more and if you've had no reason to not go to a Pontiac service center, i.e. they are nitwits....why not let check into it? Whats the price tag on aggravation?


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## FastFrank (Jun 12, 2009)

You say when you first got the car the AC was ice cold, and now it's not. That right there is an indication that there is a problem. I would pay the $40 to find out what's wrong if you really want to use your AC. My guess is that the first guy was right, and your compressor is going. Assuming he was right about it being fully charged that is. Is the compressor engaged when it's blowing warm air?


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## sleepindirty (Mar 31, 2010)

GTO JUDGE said:


> My AC works fine. You must have an aftermarket warranty? My GMPP covers the AC compressor.
> He must have it a few days while he makes some calls? Who's he going to call and it will take days to do it?
> 
> I know a lot of guys shy away from the dealer's service many view them as evil and gouging. Many have had bad experiences with them and they have their reasons for not patronizing them (understandable). I know in my area many shops labor charges are close to the same as what dealers charge for service. Many, MANY years ago service charges at a dealer were MUCH higher than those of a corner shop.
> ...


i checked with the local dealer... they want 90 bucks to check it.


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## sleepindirty (Mar 31, 2010)

FastFrank said:


> You say when you first got the car the AC was ice cold, and now it's not. That right there is an indication that there is a problem. I would pay the $40 to find out what's wrong if you really want to use your AC. My guess is that the first guy was right, and your compressor is going. Assuming he was right about it being fully charged that is. Is the compressor engaged when it's blowing warm air?



yes it blew ice cold when i first bought it. but day time temps have gone for low 80's to 100F. once the sun goes down the A/C does fine. 
im really wondering if the gto had a decent enough A/C to handel the heat. i had a camaro about 10 years ago and it never cooled the car down ... even in the winter. :rofl: was just wondering if im expecitng to much from a sports car.


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## HP11 (Apr 11, 2009)

If the system is fully charged and the discharge pressure is normal, but the suction pressure is high, (like 45-80 psi), the symptoms you describe could be a faulty refrigerant control valve. It starts out by being intermittent in that sometimes it will cool okay and other times not so much until it will ultimately just blow warm air. It's a $25-$40 part. Changing it involves evacuating the AC system, removing the the rear cover from the compressor, changing the valve, replacing the rear cover, pulling a vacuum on the system and recharging the system. Unless you know how to do this and have the equipment (I do), I'd suggest ponying up the 90 bucks.

EDIT: If I'm right, your Camaro likely had the same problem.


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## AlaGreyGoat (Jul 6, 2006)

Idling around on a hot day, mine cools, but not great. Keeping the rpms up,
it does great. Has anyone installed an underdrive pulley?

Larry


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## FastFrank (Jun 12, 2009)

sleepindirty said:


> yes it blew ice cold when i first bought it. but day time temps have gone for low 80's to 100F. once the sun goes down the A/C does fine.
> im really wondering if the gto had a decent enough A/C to handel the heat. i had a camaro about 10 years ago and it never cooled the car down ... even in the winter. :rofl: was just wondering if im expecitng to much from a sports car.


We don't get many 100 degree days here, but we did have a few last year. And the AC worked fine on those days. I would say there is nothing wrong with the design of the system.


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## GTO JUDGE (May 14, 2005)

90 just to check? The other place wants 40? If you are looking for someone to do it for free you may resign yourself to the fact you'll be without AC. 

Diagnostic fee sounds like. It's obvious you have a problem. Your warranty covers this right? But you have to go to a place under their guidelines? You'll have a deductible right? Whatever the fee is to fix this the 40.00 fee is included. So your gonna pay a deductible. Seems to me that no matter what the bill is you are liable for a deductible. If the bill is say 200 to repair and your deductible is 100 the 40.00 fee is mute, right?


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## HP11 (Apr 11, 2009)

I do live in an area where there are 100+ degree summers. The AC on my 05 has always been more than adequate. The variable stroke compressors that these cars use really need to be run at least a couple times per month during the off season. Lack of use can sometimes cause the control valve in the compressor to stick or become clogged. When everything is right, these systems are actually very efficient.


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## GTO JUDGE (May 14, 2005)

The leather will absorb some heat, black dash and interior... car sitting in a hot sun all day.... Gonna take a while to cool it down. 

Get a little thermometer and clip it to the air vent and read the temp coming from the AC it ought to be about 20 degrees cooler than the ambient temp outside.. (I think)


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## HP11 (Apr 11, 2009)

When I use my infrared thermometer, the vents will show low 30s-high 20s F. That's about what it takes to lower the temperature in the car to where it's comfortable. Just drove mine. Once I got going about a couple blocks from home, I turn the fan switch to '1' and I'm good. Today's temp here in San Bernardino is 90.


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## rcollamore (Feb 5, 2009)

My a/c works fine, but my issue is that when my a/c light goes off my a/c turns off. Does anyone know what that means?


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## ricekiller848 (Oct 24, 2007)

rcollamore said:


> My a/c works fine, but my issue is that when my a/c light goes off my a/c turns off. Does anyone know what that means?


Did you push the button and the light turned off? Or did the light turn off by itself? If it gose off by itself then you have a wierd problem. When the little light under A/C is off the a/c will turn off and you will just blow outside air in.


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## mikes06goat (Jan 13, 2009)

The light is on the A/C clutch switch if the light goes off the clutch is disengaging, which would turn off your A/C. It shouldn't turn off by itself. You should have to switch it off.


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## rcollamore (Feb 5, 2009)

it just turns off by its self. Then I switch it off and back on and it works fine. I kinda figured it had to do something with the wiring.


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## FastFrank (Jun 12, 2009)

rcollamore said:


> it just turns off by its self. Then I switch it off and back on and it works fine. I kinda figured it had to do something with the wiring.


You might want to have it looked at. It's not normal for the compressor to disengage on it's own unless the system is low on refrigerant.


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## motoristx (Apr 27, 2010)

i got a thermometer in my vent (left vent by hazard switch). I'm in Houston. 140F on a sunny day with windows up after an hour or 2 in side (yellow jacket/black int).

i have a SLP (I think) UD pulley. and the low pressure side reads 55 PSI at idle (850rpm) and down to 40 PSI at 2k. 

sitting parked and idleing my temp (same vent) gets down to about 55 F. once i drive at 65+ MPH for 5 -10 mins, the temp gets down to 40F(same vent). this is on Max cold with the selector on recycle, and on output speed #4. if you turn the speed down, it gets colder, but at a lower speed.

i noticed at night, it has gotted down to 30F - 35F at the vent.

most hot days so far have been around 90F - 95F ambient temp, and about 75F - 80F at night.

hope this helps.


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## HP11 (Apr 11, 2009)

You description doesn't sound quite right. I use an infrared thermometer. My vent temps are lower even at the side vents. After the interior cools, I switch mine to speed #1. Vent temps will drop into the high 20s occaisionally and never get above the mid 30s @ idle in the daytime. It's very hot here in San Bernardino also. 100 degrees plus on a hot day. 55 psi on the suction side @ idle sounds slightly overcharged to me. Could also be a faulty refrigerant contol valve but you have the read both sides to make that determination. (See post #7)

*EDIT:* I just thought about another factor. You say that you have an UD pulley on the compressor? That slows the speed of the compressor which raises the suction pressure. That has to be compensated for. If you decrease the pressure @ idle to about 35-40 psi, your system will cool better.


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## Poncho Dan (Jun 30, 2009)

I haven't used my A/C since I bought the car a year ago. Up here in WI you can get away with not having it, and I will delete my system 100% upon failure. Up until my Grand Am, I never had a car with A/C, just windows that rolled down... even tho the unit on that just took a dump. :rofl:

I realize how useless that becomes as the outside temperature climbs above 95ish... but again, thats... 1 day a year here? :lol:


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