AC warms slightly at stops

[gnsrule]

Flowage is the answer !!! Freon is going from a Hi pressure gas to a low pressure liquid at the orfice tube. As the freon goes thru the tube, it gets colder by laws of physics. You need the flowage to make that happen. But, guage reading would be a clincher. If hi and lo side are low at idle, its lack of compresser output or low on freon, but if the hi side goes up and low is normal to hi, id look for airflow thru the exaporator. Maybe add an extra fan or check the skirting between the grill and the rad suport.
Who did the recharge, an over charged system wont cool either, and if ya open the system for any reason, dont forget to replace the dryer.
Whatever ya do tho...dont expect new car a/c out of these. They wont cool like the new stuff, but i think thats more on the order of insulation since the air in the duct work is around 34-40 w/ 12 or 134.
A/c is all in the guy who's doing it. Chargeing stations are nice, vac pump, reclaim, recycle, and guages all in one are nice. And they even puter charge it for ya, but guages work fine if ya know how to use em
Hope this helps

 

[dpok69]

I think something is definetely wrong with my system. I was driving around yesterday in stop and go situations, and it was better for me to just leave the windows open rather than having my AC on. There would be 20 sec periods where the air became warm even after moving the car.

Even when i got on the highway, i experienced warm air for 20 secs then it started it cool down. i know my check valves for the AC are shot cause if i go under boost the AC stops blowing from passenger vents, and rather into the foot area.

The people who did my system where almost like backyard mechanics. It was actually a radiator place. They did not look to modern. Im jus gonna bring it into a proffesional place, and hope they can solve the problem.

I did not want to go with 134A, cause it raises the engines temperture. And R-12 is supposed to be cooler.

May also have a leak, cause last year when i had no freon, i was working around the k&n filter and accidently put pressure on the AC hose. I saw little bubbles and film (oil) come out only when pressure was applied.

Its embarassing having my wife in the car and sweating like a pig . Its so bad in hot weather, id rather stay home then go through stop and go situations.

i found this good post if any of you are planning to have your A/C checked out or recharged Post

 

[ITSAV6]

another check

Stupid me! Forgot about this,after having my car about a year I also got varying hot and cold air that no one could figure out,it was the heater control valve that was stuck and was flowing water through heater core. I accidentally found that one when back flushing rad. and took it off to put in the tee for flushing and saw that it was open 1/4 of the way and couldn't close it. Shot it w/PB Blaster and freed it up til I got a new one. Hope this helps-just popped in my memory this A.M.!!
I was told by an AC tech to turn your AC on 1-2 times a week in the winter and it will keep the seals from leaking in the "off season". Like cranking a car that is kept in storeage needs to be cranked to keep seals from drying out.

 

[dpok69]

I got the aftermarket heater valve. I hope thats not the problem. The aftermarket one is black and plastic. And the original heater hoses do not work with it, so i had to buy heater hoses and cut to length.

i also back flushed my radio using the prestone kit with the T. It was easy for me to T in with the additional length of heater hose that existed from from the new install of the heater valve.

 

[FlyinGN]

Flushed your RADIO?? Why, thars yur problem bub....

Flushing your radio won't help ya ONE bit keeping your car cooler BUT it will help make the stations come in clearer..

seriously, it sounds like your compressor clutch is going or your heater control valve is passing..

 

[dpok69]

Took my car to the A/C shop today. The system only had 1.24 pounds. Our system is suposed to have 3.25 pounds. He filled it up with Freeze 12 and checked for leaks. Took him almost an hour to do everything.

But i still have warm air sometimes It turns out the low pressure switch? by the accumalatot turns the compressor on and off intermitently (more off than on though). When he shorts the plug, the compressor turns on, and when it is connected to the switch it does not alaways turn on. He wants me to bring the car back on monday.

if he needs to evecuate the system again, is there anything i can replace that will increase the sytems cooling effieciency?

 

[BoostMasterK]

I don't think anyone mentioned this yet, but did you jump your low speed fan resistor to make it a high speed fan all the time? This not only helps keep the AC cooler, but keeps the coolant cooler too. It's easy to do and I consider it mandatory with these cars.

The weatherstrip around the fan shroud is also a good idea I have to try that.


Mike [

 

[dpok69]

I did not jump my low speed resistor yet. I have to look into that. i am planning on replacing my radio core too.

i just had my low pressure switch replace today. The compressor stays on but, the AC was not as cold as i expected it to be. i should put a thermostat on the vent to check to c if my system is running in its proper range.

i am thinking now i may also have a heater valve fault. How can i check this? Can I run my car till its hot and unscrew the prestone T on the heater hoses to cehck for coolant passing? My car reached a temp of 214 today before i shut the AC off.

Oh yeah, sometimes when i shut off the AC it makes a weird squeeling sound from behind the AC control unit (not the swoosh sound which is normal)

This AC thing is really pissing me off. I have a newborn and a wife that always complain or cry that it is hot!!!!

I wonder what changing the compressor would do for me if all else fails?

 

[Steve Wood]

Mike, I think the fan should be on high when the ac is on. If it is not, then it is probably a bad relay.

A set of gauges should tell you if the compressor is working well enuf. Our cars have tired condensors and it may not be removing as much heat as it should.

Contrary to claims, most of my experience indicates that the substitute freons don't work as well as they should.

 

[dpok69]

Okay, i went to the shop again today and told the mech that the AC is still not cold enough even in 80 deg weather. He told me to bring it back on Monday. He thinks the orifice might be clogged and he was gonna clean it. He told me he has to evacuate the system again to do this. (Hopefully he want charge me for that)

Well, i took this moment and went to my auto parts store. i asked for a variable orifice and they looked at me weird and questioned my knowledge. The guy said he only has the OEM orifice, but when he looked in his computer he also saw a listing for an automatic orifice. So i bought that, considering there was a huge price difference from the OEM one, $5 vs $30 like some have posted here. Both store personel learned something new in there 5+ years of experience in the store when i mentioned what its purpose is.

Opened up the box when i got home and it came with directions. It said to replace the accumalator. So i will be buying that tommorow. It also says there is a heavy duty version also. I got the regular one not knowing this. The heavy duty one is made for Arizona type weather conditions, where the average temps are 105 deg or higher and has red coloring on the orifice.

My mech is using Freeze 12. And i was happy cause it was supposed to be colder than r12. But i read another post that says that it is extremely flamable. One of the ingredients is propane. i have already invested in this shop so i am not going back to another shop for r12. Instead i will be getting a fire exstiguisher, which i think are cars need anywayz.

Well, i will post results with my ordeal after monday.

 

[Steve Wood]

cannot believe everything you read.

Freeze 12 is advertised as non flammable but it does have a little butane in it.

You only need the can if you are converting the system or the compressor blew. I think I paid about 25$ for one at Autozone the other day. Not a big deal. Certainly won't help. And yes, he has to evacuate the system but he should have a recovery tank. If you are changing to Freeze 12, then it does not matter.

 

[dpok69]

What can are you refering to Steve? The accumulator? I got a price on it today for 48$ from a smaller auto parts store. If it wont help any, i wont buy it. I should check the price at my local pep boys.

 

[Buzzard]

First off, avoid using the substitute refrigerants like Freeze 12, I have not had any luck with any of them. I would also avoid using 134A the effiency is not as good using the stock condensor. 134A was developed for newer cars using a different style of condensor than we have. I believe the can he is refering to is the accumulator or sometimes called the reciever/dryer. The main thing to remember is that the only way to cool the inside of the car is to effectivly transfer the heat from the inside of the car to the outside, this requires a compressor that is working properly and a cooling system (radiator, cooling fan, t-stat) that is up to snuff. Some warming of the outlet temp is normal in stop and go traffic due to the lack of ram air over the condensor, a better cooling fan can help this by drawing more air over the coils of the condensor. Using a good set of A/C gauges you should get readings at idle on a 100 deg day of around 45 low side and 250-300 on the high side. If you don't see this you need to find out why. Any ASE certified tech should be able to diagnose your A/C system and tell you what's wrong. Spend the money to stay with R12 it works the best.

 

[turbojimmy]

Originally posted by Buzzard
First off, avoid using the substitute refrigerants like Freeze 12, I have not had any luck with any of them. I would also avoid using 134A the effiency is not as good using the stock condensor. 134A was developed for newer cars using a different style of condensor than we have. I believe the can he is refering to is the accumulator or sometimes called the reciever/dryer. The main thing to remember is that the only way to cool the inside of the car is to effectivly transfer the heat from the inside of the car to the outside, this requires a compressor that is working properly and a cooling system (radiator, cooling fan, t-stat) that is up to snuff. Some warming of the outlet temp is normal in stop and go traffic due to the lack of ram air over the condensor, a better cooling fan can help this by drawing more air over the coils of the condensor. Using a good set of A/C gauges you should get readings at idle on a 100 deg day of around 45 low side and 250-300 on the high side. If you don't see this you need to find out why. Any ASE certified tech should be able to diagnose your A/C system and tell you what's wrong. Spend the money to stay with R12 it works the best.

I converted to 134a last year. Since then, it all leaked out through a bad o-ring. I just couldn't bring myself to spend the money for an R-12 recharge when I still have 15 year-old hoses and other stuff. I made the initial investment in the manifold gauges and conversion kit, but it cost me less to convert than it would've been to bring the R-12 up to snuff. 134a is $4.50 a can at WalMart and I can charge it up whenever I want.

With the settings you mentioned 45-50 on the low side and 250-300 on the high side (high 80s today) I get 38-40 degrees at the center outlets. Idling in my hot garage, it creeps up to the mid-50s. I don't know what the R-12 was like 'cause it never worked, but the 134a works just fine.

Jim