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turbobuick33 07-30-2008 06:52 PM

AC blows warm when idling
My gf has a 95 sc2 and the AC blows cold while driving but when coming to stop or when the car is idling the AC becomes warm and not cold. What would cause this?

OldNuc 07-30-2008 07:32 PM

Re: AC blows warm when idling
Either too much or not enough gas. The refrigerant charge is critical for an R-134a system. Also a condenser with lots of bent fins will do the same thing.

Swapped96Sc1 07-30-2008 08:49 PM

Re: AC blows warm when idling
yea i would check the refrigerant level. also ive seen this alot: people will drive with the ac on for a while and then when they get home they will shut there car off with the ac at the same time. well the problem with this is when your ac is running it gets condensation(water) on the condenser so when they shut the car off the condenser has water on it and it will sit and after multiple times will start to mold. once mold forms it will block the air coming in(much like a bunch of bent fins) and is hard to get off and might have a little smell to it.

the way to prevent this is about a minute or two before you get home turn your ac off and just roll the windows down. that will give your condenser time to dry off as you drive. just eough time so its not wet. hope that helps some.

CoreyB105 07-30-2008 09:31 PM

Re: AC blows warm when idling
this is kinda a problem w/ me, i have a 01 sl1 and i changed my oil and was reseting the oil fuse thing under the hood and noticed how dirty under the hood was so i started cleaning it and then my ac suddenly started to work again not blowing cold air (id say cool around 70*F) but not like hot air that it was before so i think some of the cleaner dropped on the condenser and cleaned it a bit. i just have no clue where the condenser is i can see the radiator coil is (thing in the front where i cant remember its name but cools down engine) and i know its somewhere near there but im not sure if i need to go underneath the car to clean it/wipe it off depending on how bad, or if its accessible from under the hood verses under the car. also if you have pics pointing in the right direction that would be great cuz ive tried google/yahoo/metacrawler/ect. and nothing really showing where anything is. just the engine itself. thanks in advance

Swapped96Sc1 07-30-2008 09:42 PM

Re: AC blows warm when idling
the condenser is located right in front of the radiator. if you look from the front of the car at the front bumper you can see the condenser right behind the front bumper. it has fins almost looks like the radiator. ill try to find a pic

hope that helps.

OldNuc 07-30-2008 09:56 PM

Re: AC blows warm when idling
Aluminum fins bend very easy. Do not use a high pressure stream of water to flush it off. Flush from the back side with a garden hose and a slightly spread spray. Back side and then front side. If its real bad spray it down with 409 first.

The condenser and evaporator have to be clean to have any chance of properly determining the state of the charge with gauges.

CoreyB105 07-30-2008 10:09 PM

Re: AC blows warm when idling
ok so ill look again i used some wd40 to clean some of the metal parts that i know wouldnt be mechanically effected and that worked really well on getting the dirt and grime off, is that safe to use for cleaning it or should i just use water to make sure nothing mechanical gets messed up.

OldNuc 07-30-2008 10:13 PM

Re: AC blows warm when idling
Water and 409 will work wonders. WD-40 is good for cutting grease but a paint brush or sprayer and diesel oil is cheaper. If you use diesel oil follow up with 409 after a couple of rinses. Any of the spray kitchen cleaners will work but you can buy 409 by the gallon at SAMs and it does get rid of most of the gunk. **Do not use any oven cleaners or other liquid cleaners that are not safe for aluminum. Read the label.

CoreyB105 07-30-2008 10:29 PM

Re: AC blows warm when idling
ok 409 and water it is thanks ill let you know my outcome tomorrow because right now its 10:30pm and i dont think my neightbors would be to appreciative

fdryer 07-31-2008 12:31 AM

Re: AC blows warm when idling
[QUOTE=turbobuick33;1291610]My gf has a 95 sc2 and the AC blows cold while driving but when coming to stop or when the car is idling the AC becomes warm and not cold. What would cause this?[/QUOTE]

You're either gonna' be a hero or jack*** to your gf (there's just no middle ground unless the car is taken to the a/c shop) if you do the following; [url][/url]. [B]If[/B] you make a real honest effort to look real hard for evidence of a leak and can't find any, you should be able to use a refill can of R134a with dye ([B]only[/B]). [B]Do not use any miracle sealer![/B] If you don't spend the time to look for the source of the leak and refill, there's no guarantee of this refill lasting a day, a week or the rest of the season. A/C systems are sealed and pressurized and not to be refilled every year, week, or monthly. The fastest and easiest leak is right at the service port where refrigerant is injected into the system. Cheap store can refills with plastic quick couplers may cause an incorrect connection and/or seem like a connection without actually depressing the valve stem (that allows refrigerant into or out of the system). It can also lead to complete discharging of the system when these quick couplers are disconnected and the valve stem doesn't re-seat properly. Just the little things to keep in mind for those that think its so easy to simply refill and drive away. Yes, it can be that simple but when things go wrong they go wrong in a big way unless you're prepared ahead of time.

Being prepared may mean spending money to buy a real screw-on can tap that pierces the sealed R134a can and allows precision amounts of gas/fluid into the system along with a real hose with a real metal fitting that can be used over and over. Its your choice and your risk when working around airconditioning systems. Servicing a/c systems can be done, when done correctly, but if using cheap equipment and disaster occurs......................

Buy a dial type thermometer to insert into the center vents, a/c on medium fan speed, all windows open, the car preferably in the shade with a fan blowing into the radiator. Have the can of R134a w/dye attached to the hose, purged the hose, and attached to the only fitting that will accept the low pressure hose fitting - the rear end of the compressor. Here's where the seriousness of a/c work cannot be stressed enough. [B][COLOR="Red"]If a refill can were somehow attached to the HIGH pressure side, the valve opened and the compressor running, AN EXPLOSION CAN OCCUR! ! ![/COLOR][/B] The [I]compressor (discharge side)[/I] can output as high as 250psi+ (the rated safety vent valve will only open at around 450psi!) so incorrectly hooking up on the wrong side can and will result in disaster, injury, and a very rude awakening of inept, poorly informed, untrained DIYer's forcing a fitting when fittings were designed to prevent this from occurring. Don't take this personally but if you don't know which fitting is which (I'm addressing anyone and everyone reading these threads) and don't make the effort to find out then you're better off leaving a/c work to a pro. Its that simple.

Careful co-ordination of regulating engine speed with or without someone else behind the wheel, E-brakes applied, in PARK or NEUTRAL can ensure a safe working environment otherwise carelessness can lead to..................

With the R134a attached to the service port (suction side) and the valve closed, start the engine, turn on the a/c (with the compressor running), run the engine up to 1500rpm and hold it there while opening the valve so the refill can will dispense refrigerant. Monitor the interior temps while injecting refrigerant. Keep the can upright and as the can becomes very cold, have a small pail for very warm water to partially submerge the can into to transfer the warmth to the can contents. As soon as interior temps approach 45F stop injecting refrigerant by shutting off the valve. Watch the temperature dial for the next few minutes as the a/c system stabilizes. If the temps stay, this can left this way (depending on outside temperatures) and everything disconnected or carefully dispensing a few ounces more of R134a and closing the valve to watch the dial thermometer. Overcharging here will lead to higher HIGH-side pressures and begin to raise the cold temperatures instead of lowering it. Carefully feeding a few ounces and halting the feed while monitoring the dial thermometer will show whether or not temperatures will drop. Be very careful not to add anymore R134a than necessary. Don't try for lower temperatures by injecting more refrigerant. 40F is the absolute lowest with a car standing still and a fan blowing into the radiator as this isn't driving at highway speeds at higher rpm. Both will lower interior temperatures as a/c efficiency improves at 2000rpm. Don't "I'll just throw in another half can for reserve in case of a small leak or so I don't have to do this again for another year" make the excuse to overfill. Use just enough and stop, period. Give away the rest of the can's contents to someone else or leave it on the shelf as there isn't any shelf life of refrigerant. It stays fresh as long as the gaskets and valve seals work, preventing any refigerant from leaking out. Your gf's car should be good to go.

scottyboost 07-31-2008 08:56 AM

Re: AC blows warm when idling
Are you sure the cooling fan is running?

CoreyB105 07-31-2008 03:09 PM

Re: AC blows warm when idling
ok so i did what you guys said and then ran the ac for around 5 minutes and not much improvement. still no leaks anywhere from the car so i dont think the ac system has a leak anywere causing it to have air get into the system i cleaned everything very well and still nothing. i think if any leak it was an extremely small one that still hasnt completely drained the system even after 7 years so do you think i should just go get a recharge when i get the cash because thats a long time if any leak had occored and would not effect me too much if it needed to just be recharged every 7 years. also if you can think of anything else that would make it better that would be great.

OldNuc 07-31-2008 05:00 PM

Re: AC blows warm when idling
When you switched on the A/C did the cooling fan start? It is supposed to, check, lack of fan will cause hot A/C. If the cooling fan starts then you are probably low on gas.

CoreyB105 07-31-2008 05:27 PM

Re: AC blows warm when idling
well the fan in the car works, air comming out of dash, that blows stong and when i hit the ac button no real change in air speed, but when i put the circulate cabin air button the cars fan almost doubles in speed so... ?

scottyboost 07-31-2008 08:00 PM

Re: AC blows warm when idling
The radiator fan. That's the cooling fan. It should be on whenever the AC compressor runs.

OldNuc 07-31-2008 08:27 PM

Re: AC blows warm when idling
Yep. Start car, let it warm up, push the A/C button, open hood and look and see if the cooling fan is running. It is supposed to start when the A/C is on.

CoreyB105 07-31-2008 08:44 PM

Re: AC blows warm when idling
ok will check when doing brakes and possibly ects, tomorrow.

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