# A/C seems weak and isnt blowing very cold. Anyone have similar problems before?



## justin-branam (Oct 31, 2008)

Quick update:

took it to the dealership and guess what, they found nothing wrong. Here is something new i have noticed though. When it is set on re-circulate and on #4 a/c, it almost froze me out of the car like normal, but crank it to fresh-air #4 a/c and thats where the problem is. on re-circ, the low pressure side pipe at the firewall was sweating like crazy and was cold, while the high-side pipe was barely warm to the touch. ran it on fresh-air for about 5 minutes and the low pressure side was bone dry, warm to the touch, and the high side was scalding hot. can anyone explain this? would this be some kind of relay not functioning right?

and also, can anyone verify if the cooling fans are supposed to cycle between low and high speed while the a/c is on? 


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All of the sudden today my a/c seems out of whack. I drove the car this morning on the highway and in town and didnt notice it acting up. This afternoon i took my dad to the doctors office, and we both noticed it didnt seem to be pushing hard or seem very cold. yesterday was just as hot outside, so i dont think that has anything to do with it




Here are my symptoms and observations:

-blower seems to be weaker than normal

-a/c is definitely not as cold as it used to be

-high pressure side seems very very hot to the touch and is hitting over 300 on the guages

-low pressure side was hitting up and just above 60 on the guages (should be closer to 45 right?)

-condenser coil is also very warm

-fans cycle between high and low power while the a/c is on (is this normal? thought they were supped to stay on high power with the a/c on)

-wires going to the fans seem to be very hot

-alternator is testing just on the border of being okay with my personal voltage tester





I thought at first maybe i got a hole in the condensor coil or something from a rock, but with the pressures as high as they are, it almost seems as if the system is a bit overcharged. I am leaning towards a few things:


1) alternator is going bad and the fan is not running at the correct rpm's. the blower could also not be getting enough power to run correctly. the fans could be pulling more amps due to the lower voltage so i guess this could make the wires hotter. 

2) electrical issue with the fan. i thought both were supposed to be on high power the entire time the a/c is on. am i mistaken here? they were definitely cycling between hi and low power.

3) someone put a hex on my car




Other than that, i cant think of why this would be happening. anyone out there had similar problems? im going to go get the alternator checked out at autozone tomorrow, and if it checks out, i guess its on to the stealership for a diagnoses.


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## Poolshark1321 (May 18, 2009)

I also live in Houston and have been driving around in this hot, sticky, texas summer weather... although I have no problems with my A/C, its cold as ICE.

I would do as you were talking about though... process of elimination is one of the best ways to diagnose problems on your own. 

Also Ive heard that underdrive pulleys can have effects on things that need power on your car.

Heres a post about underdrive puleys that I found helpful in making the choice to not get one... ever!

Underdrive Pulley Tech - Purdue Automotive Performance Association

Hope you can figure it out... if all else fails take it to the dealership and cross your fingers that its covered under warranty.

GL!


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## GTO JUDGE (May 14, 2005)

You may be low or out of refrigerant. There may not be enough pressure in the system due to low or out of that refrigerant. Try turning the heat on and see if the blower is working ok.

I am suspecting you need refrigerant. Have the system pressure tested if theare leaks address it.


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## justin-branam (Oct 31, 2008)

GTO JUDGE said:


> You may be low or out of refrigerant. There may not be enough pressure in the system due to low or out of that refrigerant. Try turning the heat on and see if the blower is working ok.
> 
> I am suspecting you need refrigerant. Have the system pressure tested if theare leaks address it.


i did check the refrigerant levels:

"-high pressure side is hitting over 300 psi on the guages

-low pressure side was hitting up and just above 60 psi on the guages (should be closer to 45 right?)"

this indication eliminates the option that i have lost refrigerant. if i put any more in there, im likely to way overpressurize the system since it seems like it is a bit overpressurized already. oh well, off to autozone for a alternator check.


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## justin-branam (Oct 31, 2008)

quick update (to all 2 of you who are the least bit interested):

battery and alternator checked out fine. guess ill drop it off at the dealership monday morning. at least i still have my bumper to bumper until november this year. hopefully its just a bad relay or something. uugghh, the joys of owning a vehicle


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## GOATTEE (Nov 30, 2006)

I know something is wrong with your A/C. This is the coldest A/C I have ever felt in my car.


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## jetstang (Nov 5, 2008)

That's odd the pressures are that high, but that may be typical pressures. My 99 Vette blew hot air out the drivers side, it ended up being the actuators on the ac box lost there reference point. So, I had to pull fuze 27 for 60 seconds, then reinstall, the computer thinks you replaced the relay, so it runs it lock to lock to find the home position, now my AC blows ice cold. May work on the GTO, I don't know what fuze you would pull, but it has to do with the HVAC system, not the compressor, my heater display went out when I pulled the fuze. Or you may have a bad actuator.


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## justin-branam (Oct 31, 2008)

guy at the dealership said he thinks there is some kind of blockage in the system. personally i would think the suction side pressure would be a lot lower if thats the case, but its been a full day in the shop and im starting to miss my car already.


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## Phil (Apr 30, 2009)

I have a 06 GTO with 19400 on it and last week my compressure started to make a lot of noise. And you can guess, I no longer have A/C. The worst part about it I just pass my three year mark with the car last month. So no Pontiac dealership will cover it. If anyone knows where I can get a cheat compressure hit me up....................


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## justin-branam (Oct 31, 2008)

please check out the quick update on the first post. thanks.


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## Zebra (Sep 2, 2006)

My AC has never been outstanding. On a scale of 1-10, I'd give it a 3. I used to hear a growling sound when I pushed the AC button. A friend told me to check resevoir coolant so I did and it was virtually empty. I filled the resevoir with DEX-COOl 50/50 pre-mix and the growl is gone. And, I bought a gauge to check my coolant, which says it's around 35 psi. 

Just to be sure, I'm supposed to attached the gauge to the low side. Is that located on the passenger side? Does it look like a little silver cylinder with "nipple" on top?

I did all of this just in the last 2 days.


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## REDDOG (Oct 25, 2008)

Ref- A/C not blowing cold enough. I blew a hole in 1 of my A/C lines (05 GTO LS2). The line that runs against the top of the firewall. As it was originally installed, it ran from the passenger side, then down underneath the steering column and then towards the front of the car. The steering column ate a hole through the A/C line and the cluthch line. So they both went out at the same time. Imagine that, right!? Needless to say, I was PO'd to the max. I found an aftermarket cluth line, less than $120.00 shipped, stainless steel and a way better design than the original crap GM put in. Check out Classic Tube - PreBent and Custom Stainless and OE Brake Lines and more... for future reference if that ever happens to you. It wasn't a bad install and much better for the long haul I'm sure.

Next I got the A/C line from a local Pontiac dealer. It costed less than $100.00 shipped. I took the radiator out and all the front end stuff attached to it. It all came out pretty easily in a short amount of time. Had to drain the coolant. No big deal. I took out the big plastic intake tube going from between the throttle body and air filter. There's a few wiring connectors you gotta be careful with, but it's all gravy. If all else fails, take pictures and notes to keep up with things. The old A/C line broke in half right where the huge hole was while I was trying to remove it. The new A/C line went in with minimal effort. It's pretty easy to bend, so I ran it over top of the steering column, with about an inch clearance like I never had before. Once I put it all back together, I went to Wal-Mart and grabbed a couple of cheap cans of freon that come with the psi gauge. I charged the system and got cool air to start with. The gauge display caution mark is just after 45 psi. But today I got a handout from Autozone, which states the outside temperature should be taken into consideration as to what the psi gauge should read. I live outside of Dallas, TX. It was 103F degrees today, and much more with the heat index. With such a high outside temp, the handout says I should push the psi to 50-55 psi. So I got a 3rd can of freon and put more into the A/C system untill I got to just above 50 psi. I punked out after that LOL. The A/C seems to be alot more cooler than it was after the repair I did. I plan to tweek it further and post an outcome.

If your system has a minor leak, that may be your problem. Because my A/C didn't go totally out all at once. It was more of a gradual thing until about 2 days before the clutch line totally sprung a leak. Next if the system has ever been opened up for repair, like I just did with mine. It should actually be vacuum flushed and filled with fresh freon. That takes care of any air and moisture that may have entered the system. That's my next move. I just went the cheap route to make sure I had no leaks. I figure for chump change, I could find out alot on my own. Before taking it to the wolves for repair and or flush and fill.

And lastly, I've also heard about pulling related fuses to reset things. I tried that as well and that didn't seem to do anything, but bust my knuckles.

Hope some of this was useful. Good luck.


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## REDDOG (Oct 25, 2008)

Zebra said:


> My AC has never been outstanding. On a scale of 1-10, I'd give it a 3. I used to hear a growling sound when I pushed the AC button. A friend told me to check resevoir coolant so I did and it was virtually empty. I filled the resevoir with DEX-COOl 50/50 pre-mix and the growl is gone. And, I bought a gauge to check my coolant, which says it's around 35 psi.
> 
> Just to be sure, I'm supposed to attached the gauge to the low side. Is that located on the passenger side? Does it look like a little silver cylinder with "nipple" on top?
> 
> I did all of this just in the last 2 days.


Making sure your coolant level is topped off is always a good thing. You're correct on the A/C low side and where to attach the gauge. Most of the non-pro refrigerant/freon gauges will say go to 45 psi. But the outside temperature supposedly makes a difference as to what reading you should push it to. Autozone has a free how to charge A/C handout that explains it pretty well. Check it out. Good luck.


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## jrbarnes455 (Apr 19, 2009)

justin-branam

Did you say the car freezes you out on recirculate but on fresh air it gets warm? I have to ask has anyone changed the cabin filter because that could be dirty and you are not getting any airflow and the cabin filter would only affect the fresh air side.


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## badgoat91 (Jul 13, 2009)

i cant even find a cabin filter on my goat, where the hell is it? im starting to think there isnt one


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## jrbarnes455 (Apr 19, 2009)

I don't belive it has one after checking further into it but, the fresh air intake is in the cowl under the wipers and if you get alot of leaves on your car there may be debris clogging the screen and not letting air in. 

You'll have to remove the wipers and the cowl screens and then you get to the screen for the fresh air inlet, you could clean that one or a new one from GM for about 20 dollars.


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## jrbarnes455 (Apr 19, 2009)

I checked at work today and there are some problems with the fresh air intake screen being clogged with debris as I read in a service bulletin from GM


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## stangeater (Jan 17, 2006)

It could be the TXV valve not working correctly. For A/C to work correctly you have the have the proper amount of refrigerant coming into the evaporator. The TXV throttles the amount of refrigerant going into the evaporator by the temperature of the gas coming out of the evaporator. When you have the recirculation on there is less heat load, because your just trying to cool air that is already some what cool. But when you are trying to cool the air from out side that is close to 90 degrees, that puts a bigger heat load on the system. when you heat load is low the refrigerant is still evaporating from liquid to gas as it is coming out of the evaporator. That's why the pipe coming through the fire wall is cold. With your high heat load all the refrigerant is evaporating before it gets all the way through the evaporator. When it does this it starts to superheat the gas which is why the pipe is warm. At 60 psi 134-A is evaporating off at 62 degrees. At 45 psi it is evaporating off at 49 degrees. Lower pressure colder evaporator temp, to a point. When it get to cold it freezes.

Those pamphlets from auto zone are more geared towards systems that have orifice tubes. Orifice tube are a fixed metering device, TXV's are a variable metering device.

On the fan issue the computer runs the fans by the pressure of the high side. The higher the pressure the higher the fans run. 

Hope any of this can help you out.

This is just a suggestion not saying this is your problem


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