: A/C Question



jguelcher
03-09-04, 07:03 PM
Ok, I have a running argument with someone. My air just stopped running cold before the winter, and with the Florida summer right around the corner, it's time to get that taken care of. The compressor seems to turn on, so I don't think that is the problem.

I'm guessing, that the refrigerant has just run low over the years (96 Deville).

The argument, is that I'm saying that over the years, the refrigerant can just "run low", without actually having a leak. He says that isn't the case, and that if you need refrigerant, it can only mean that I have a leak somewhere.

HELP! Thanks.

Note: If this is in the wrong forum, feel free to move it ;-)


Edit: What type of refridgerant does a 96 Deville take. I think I'll probably just go and have someone add a lb or two, whatever it needs. But I'm also contemplating doing it myself. Thanks.

Vesicant
03-09-04, 08:08 PM
Usually, it just needs a recharge (the psi drops in the refrigerant when its cycled enough) and occasionally your going to want to add some more, but thats alright. If you loose all of the refrigerant, then thats a problem and that signifies a leak. DO NOT do a recharge yourself or add more, if done improperly you can run a risk of explosion or other dangerious occurances... not to mention frostbite. It is best to take it to a mechanic that is certified to do the process and is using capable equipment.

Your car is equipped with R-134a.

Note: You can add more, but you must have a PSI gauge connnected first to see if you need to add more... its still dangerious and is best left to the pros.

Lawrence
03-09-04, 08:16 PM
The answer is yes, and no. It does naturally leak or it would all be in there. However you are right in that it is normal for it to leak out over some period of time. Automotive systems are not 100% tight because of all the seals and movement. Like say the system in your house or refrigerator, in which all the connections are solder because they don't move.

1996 should have 134a but check the tag on top of the accumulator.

I doubt the problem is low freon if the compressor is running as the compressor should shutdown if the freon gets that low.

Does the fan work?

jguelcher
03-09-04, 08:54 PM
The fan works fine. When I first bought the car a little over a year ago, I noticed that it mostly blew out cold, but sometimes for a minute every 20 minutes or so it would only blow out cool. I think the 1 minute turned longer and longer until it just wouldn't blow cold anymore.

Lawrence
03-10-04, 12:15 AM
So it is blowing cool now, just not cold?

jguelcher
03-10-04, 04:20 AM
Hard to tell because it's been cool outside.

zonie77
03-10-04, 09:30 AM
You will have to look at the compressor clutch while the car is running with the AC on. You want to see if the hub locks and spins the compressor. If the outer plate isn't moving the clutch isn't locking.

All auto AC units leak so your friend is correct. How can it "run low" without a leak? New units leak very, very slowly. As the rubber hardens and ages the leaks get larger.

You can recharge it yourself but check out some of the AC sites on the net for proper procedures. It isn't hard but you want too do it right and be safe. If it doesn't last long after recharging you can start looking for a leak.

Some people have had problems getting the compressor to cycle after running it with low freon. It was recently suggested to disconnect the battery for 15 sec to clear that code.

BeelzeBob
03-10-04, 11:46 AM
Usually, it just needs a recharge (the psi drops in the refrigerant when its cycled enough) and occasionally your going to want to add some more, but thats alright. If you loose all of the refrigerant, then thats a problem and that signifies a leak. DO NOT do a recharge yourself or add more, if done improperly you can run a risk of explosion or other dangerious occurances... not to mention frostbite. It is best to take it to a mechanic that is certified to do the process and is using capable equipment.

Your car is equipped with R-134a.

Note: You can add more, but you must have a PSI gauge connnected first to see if you need to add more... its still dangerious and is best left to the pros.


You must own an AC shop and are trying to drum up business...!!!!...LOL

Adding some refrigerant to an automotive AC system is one of the simplest and easiest things in the world to do.....

Explosion..????....I guess anything is possible but exploding anything putting some refrigerant in is pretty unlikely.



Just go to any autoparts or discount store and buy two cans of R134a refrigerant and a charging hose/adapter. They are little blister packed kits on a card hanging on the wall of any discount or auto parts store. Tap the refrigerant can with the adapter in the kit, hook up the hose to the low side (the fittings are errorproofed so it is pretty hard to do it wrong) and turn on the AC. With the engine running make sure the AC compressor is engaging by watching it. If you have someone turn it on and off you can easily tell when the AC clutch on the compressor engaging. IF the low refrigerant code is set disabling the AC compressor, disconnect the negative battery terminal for 30 seconds to reset the code so the compressor will run long enough to get the new refrigerant in. With the engine running and the AC on and the refrigerant kit hooked up open the valve going to the refrigerant can and turn the can upside downwards to fill from the bottom so the liquid is rapidly sucked in. That is all there is to it. Put in two cans and you will be fine.

The refirgerant charging is made a big mystery so as to get people to go to an AC shop to get the work done and pay more for it.... Just get the cans of refrigerant from Walmart and a hose kit and do it yourself.

True, there must technically be a "leak" for the system to go low on refrigerant...but....the "leak" is likely normal loss of refrigerant thru some of the fittings and pores of the hosing. The R134a has a greater propensity to leak than the previous R12 refrigerant. If you had a serious leak you would be getting a "low frigerant" warning message and the system would rapidly loose function. I would suspect you have a "normal" slow system leakdown/loss of refrigerant that is easily corrected with the addition of two cans of R134a.

I have to add a can of R134A to one of my cars that is a 94 about every other year....perfectly normal. It takes me about 30 seconds from the time the hood goes up until I close it. It is so simple and easy that for anyone to use scare tactics of explosions and such is ludicrous. Observe simple safety precautions and wear safety glasses just in case. Unless you tap the refrigerant can and open the valve so that the stuff freezes your finger it is hard to imagine a problem if you are reasonably intelligent and mechanically inclined.


By the way, there is quite a bit of leeway in the fill requirements. The factory fill spec is determined by running the system under controlled conditions in a wind tunnel to determine the optimum operating fill volume. There is a good bit of leeway there.... You would have to add 5 or 6 extra cans to start to cause any sort of serious problem with the system.... If you are low enough to observe a system loss of performance/refrigerant trouble code then two cans will easily correct the problem and be sufficient to give you good margin for performance.

There is also no need to evacuate the system to add some refrigerant. As long as the system hasn't leaked down to atmospheric pressure and/or been disconnected and opened up to allow moisture in then it is fine as is to just add some refrigearant. True that the only positive way to know absolutely how much refrigerant is in the system is to evacuate it and fill it with a known amount...but....you just want it to work, not document how much refrigerant is still in the sytem....

Do it yourself.

jguelcher
03-10-04, 03:46 PM
If you had a serious leak you would be getting a "low frigerant" warning message and the system would rapidly loose function. I would suspect you have a "normal" slow system leakdown/loss of refrigerant that is easily corrected with the addition of two cans of R134a.

Well, this brings up my next question, and one that has me a bit worried. Are you saying that there is a possibility of a "normal" leak over time that would not give me the "Low Refgridgerant" message?

After reading a few posts, I had the feeling that if I wasn't getting that message, that I probably wasn't low and there was a more serious problem. You said that you have to add a can to your 94 every year. Do you get that message every time?

BeelzeBob
03-10-04, 04:58 PM
Well, this brings up my next question, and one that has me a bit worried. Are you saying that there is a possibility of a "normal" leak over time that would not give me the "Low Refgridgerant" message?

After reading a few posts, I had the feeling that if I wasn't getting that message, that I probably wasn't low and there was a more serious problem. You said that you have to add a can to your 94 every year. Do you get that message every time?

Yes, it is entirely possible that the system is a little low from "normal" loss causing low performance....but not quite low enough to set the diagnostic code for the low refrigerant. The diagnostic code is in the system to protect the AC compressor from running with no refrigerant in it to prevent damage to the compressor...not necessarily to keep you comfortable or to tell you exactly when to add refrigerant.

Yes, you can be "low" without setting the code.


I think that you are worrying needlessly and trying to solve this "ahead of time." Try adding two cans of refrigerant. It will only cost you $15 for two cans and a charging adapter that you can use forever.... Simple, cheap and easy. If it works, then the system was just a little low and you know you will have to start adding a little every couple of years or so. No big deal. If the add doesn't solve the problem, then , yes, there may be something else wrong. Cross that bridge when you get there. Try the add first and see if the system is fine. I bet that it is. An AC shop could do a thorough leak check of the system and probablly trouble shoot all of this ahead of time (and charge you for it...you "know" they will find a leak if you are low...it will fit your preconceived notions and make you "feel" better if they do...LOL)....or you could just add the refrigerant yourself and see if that works. I would do the latter. If it doesn't work you are only out the $15 and you still have the charging connection that you can use again sometime.

zonie77
03-10-04, 05:58 PM
If it only leaks a can every year or two why go through great efforts to fix it?

Add some freon and see what happens. My understanding is the low freon comes on when it is almost empty, not when it is somewhat low.

jguelcher
03-10-04, 06:20 PM
Well, I threw in one can, and it's still blowing warm. However, it seems that when I'm driving, it cools off "a bit". Is it possible that I'm seeing a difference while driving it that I wouldn't while the car is in idle?

Also, someone mentioned actually seeing the compressor engage. I can't seem to find anything to look at. Is the compressor right there where you put in engine coolant? That silver round (edit: not round but octogonal) thing is also where I put the can in. Was that correct?

I'm such a noob.

jguelcher
03-10-04, 06:52 PM
Ok, first of all, the port I used is not on a round thing, it's actually octogon. Secondly, the can I originally put in was one with hose already attached. I decided I was doing this blindly, and have since gone and purchased the actual kit, and another can. It tells me to first check the pressure with the gauge. Gauge reads as follows..

Green - low
Blue - sufficient
Yello - overfilled
Red - OMG, Danger Will Robinson, something is seriously wrong, way overfilled or possibly hooked to the wrong port.

As luck would have it, it screamed red. So, I am now in a holding pattern to see what you guys think. Maybe I'm using the kit wrong. Maybe I hooked it up to the wrong port. I don't know.

Just to reinstate, I used the port on the drivers side next to the battery that is connected to an octogonal silver cap.

BeelzeBob
03-10-04, 10:59 PM
Ok, first of all, the port I used is not on a round thing, it's actually octogon. Secondly, the can I originally put in was one with hose already attached. I decided I was doing this blindly, and have since gone and purchased the actual kit, and another can. It tells me to first check the pressure with the gauge. Gauge reads as follows..

Green - low
Blue - sufficient
Yello - overfilled
Red - OMG, Danger Will Robinson, something is seriously wrong, way overfilled or possibly hooked to the wrong port.

As luck would have it, it screamed red. So, I am now in a holding pattern to see what you guys think. Maybe I'm using the kit wrong. Maybe I hooked it up to the wrong port. I don't know.

Just to reinstate, I used the port on the drivers side next to the battery that is connected to an octogonal silver cap.


Loose the gauge. The lawyers make them put that in there. You must have checked it with the engine off....and probably hot..??? Check it with the engine running if you want. I wouldn't worry about it. The system cannot be overcharged (which is what the gauge check is for...which is useless but that doesn't stop them) if it was low.....right?

Get the proper adapter/hose and put two cans of refrigerant in the system as described above.

The AC compressor is on the front side of the engine down at the very bottom. Look down into the engine compartment behind the radiator. The AC compressor is down at the very bottom even with the crank pulley. Follow the belt from the crank shaft to the black AC compressor. Have someone turn the system to auto and to off waiting several minutes between....you should see the compressor clutch engage on the compressor when the AC is turned on.

When the AC is running feel the lines for the AC. The High side is hot and the low side will be cold....you want the low side...the cold one....

BeelzeBob
03-10-04, 11:01 PM
BTW....you want to buy the cans of plain refrigerant. Just plain R134a. Do NOT use or buy the cans that are called AC "tuneup" or cans that have some oil in them or cans that have a stop leak in them. Any of those can ruin the system. Just add two cans of plain R134a to the low side.

zonie77
03-11-04, 12:35 AM
The compressor is mounted on the 'front' passanger side of the engine. Follow the AC lines to it. The serpentine belt goes around the pulley on it. That's the area that you have to watch to see if the compressor is cycling. That is the only place you can see it cycling.

You only read the AC pressure with the engine running and the AC on. When it cycles it will lower the pressure on one side and raise it on the other. There is a small valve in the lines that restricts the freon and gives you this difference. If the compressor isn't cycling you don't get a pressure difference.

Look at some AC web sites and get a general idea how an AC system works. That will help you understand what you are doing.

CadiJeff
03-11-04, 02:38 AM
bbob what is the likely culprit of a locked up a/c compressor in an 88 seville, I had a mech put 1 can in and he said that it was not cold enough and went ahead and put another in against my better judgement, two weeks later after a long trip the compressor locked up and almost stranded me 120mi from home, thank god for low end torque! (The engine actually ripped the clutch out of the compressor! btw the belt was 1 month old) i was thinking it could have been an over charge or possibly too little oil. What is your opinion of the issue?

jguelcher
03-11-04, 08:45 PM
UPDATE:

Ok, I was able to track down the compressor with your help, and it indeed is engaging. Now, not knowing exactly how that works, I don't know if that means the compressor is definitely working, or it just means the clutch is engaging.

I have now put a total of 2 full cans in, and there is no difference in temperature. I think the only reason it's blowing the slightest bit cool is because of the outside temperature.

At this point, I really don't know what to do next beyond taking it to someone, and hope I don't fall victim to an a/c scam.

Lawrence
03-11-04, 09:03 PM
UPDATE:

Ok, I was able to track down the compressor with your help, and it indeed is engaging. Now, not knowing exactly how that works, I don't know if that means the compressor is definitely working, or it just means the clutch is engaging.

I have now put a total of 2 full cans in, and there is no difference in temperature. I think the only reason it's blowing the slightest bit cool is because of the outside temperature.

At this point, I really don't know what to do next beyond taking it to someone, and hope I don't fall victim to an a/c scam.


If the clutch is going around, the compressor is working.

Do you have good air flow out the vents? If no, make sure the blower motor is working. If the blower motor is working, you may need to clean the outside of the evaporator. A real pain and probably best left to a mechanic.

I could also be a blend door problem but I am not really familiar with the system. Maybe someone could tell you how to check it?

zonie77
03-11-04, 09:21 PM
Lawrence is right...If the compressor is engaging (the center is spinning with the pulley) it is working. It would be squealing or knocking if it was bad.
Is there any difference when you raise the temperature?

Make sure the center hub is turning. Have you watched it while someone turns the AC on/off?

jguelcher
03-11-04, 10:06 PM
Yes, the compressor is definitely engaging. Turning up the temperature eventually turns on the heater, and begins blowing from underneath the dash.

zonie77
03-11-04, 11:00 PM
Sounds like you'll need to have someone look at it.
If you hook up the gauge with the compressor running what pressure is it showing?

jguelcher
03-11-04, 11:02 PM
150 psi. However, I believe someone in an above post told me not to pay attention to that thing.

Conflicting advice....

Lawrence
03-11-04, 11:18 PM
150 psi. However, I believe someone in an above post told me not to pay attention to that thing.

Conflicting advice....

150 PSI on the low (charging side) is way to high.

150 PSI on the high side is not enough. (Note: Do not attempt to hook a charging hose up here)(if you could)

Sounds like your compressor is bad, or you have an obstruction. Better have someone look at it before it grenades.

zonie77
03-12-04, 01:04 AM
When the AC is charged and not running both sides are equal. Usually about 80-100psi I think. When the compressor runs it pressurizes the 'high' side to about 250 and the low side drops to 25-30. If it's reading that high when running there is something wrong.

Are the hoses (pipes) from the compressor the same temp?

zonie77
03-12-04, 01:05 AM
Where are you located?

jguelcher
03-12-04, 06:57 AM
Located in Fort Myers FL. The larger of the hoses gets quite cool to the touch when running the air.

dloch
03-12-04, 10:43 AM
Located in Fort Myers FL. The larger of the hoses gets quite cool to the touch when running the air.
That is called the suction or low side hose, if the AC system is working it will indeed get cool. When it is working correctly it will get very cold, considering where you are at times may have ice on it.

How cold was it outside when you were doing this? Try letting the car sit in the sun for a while with the windows closed and try it again. You aren't by chance getting any codes about the mixer doors not working are you?

jguelcher
03-12-04, 05:27 PM
That is called the suction or low side hose, if the AC system is working it will indeed get cool. When it is working correctly it will get very cold, considering where you are at times may have ice on it.

How cold was it outside when you were doing this? Try letting the car sit in the sun for a while with the windows closed and try it again. You aren't by chance getting any codes about the mixer doors not working are you?

These are the only codes I'm getting:

IP 1552...loss of keepalive memory...battery disconnect....IPC
PC 0603...PCM....keep alive memory reset....battery disconnect.
TC 0027...left front wheel speed sensor..traction control
TC 0073....PCM-TCS interface link fault
PZ 1558...PZM eeprom check sum error

It wasn't cold at all, just cool. Probably 70 degrees. I did try letting it sit in the sun. At no time while idling did it ever blow cool. When driving, it seemed to cool down a little, but nothing nearing cold.

dloch
03-12-04, 06:02 PM
These are the only codes I'm getting:

IP 1552...loss of keepalive memory...battery disconnect....IPC
PC 0603...PCM....keep alive memory reset....battery disconnect.
TC 0027...left front wheel speed sensor..traction control
TC 0073....PCM-TCS interface link fault
PZ 1558...PZM eeprom check sum error

It wasn't cold at all, just cool. Probably 70 degrees. I did try letting it sit in the sun. At no time while idling did it ever blow cool. When driving, it seemed to cool down a little, but nothing nearing cold.
Obviously you have more problems than just the air not blowing cold but none of them seem to have anything to do with the air not blowing cold. With the air on and you raise the RPM of the engine does the compressor clutch cycle, go on and off? I am also assuming the fans are coming on as well, are they?

jguelcher
03-12-04, 06:09 PM
Yes, the fans seem to blowing normally. Actually, when checking to see if the compressor was engaging, it seemed to stay engaged even when I shut the A/C off. Now, I may have just not waited long enough, I don't know. Maybe it's supposed to run for a minute after shutdown of the system.

Two of those codes came from disconnecting the batter a couple days ago. One of them is a sensor issue. The bottom two I'm clueless about.

dloch
03-12-04, 06:12 PM
Yes, the fans seem to blowing normally. Actually, when checking to see if the compressor was engaging, it seemed to stay engaged even when I shut the A/C off. Now, I may have just not waited long enough, I don't know. Maybe it's supposed to run for a minute after shutdown of the system.

Two of those codes came from disconnecting the batter a couple days ago. One of them is a sensor issue. The bottom two I'm clueless about.
You got all of the two (16oz?) cans in?

blocker11
03-12-04, 06:13 PM
how are you reading the diagnostic codes on the car? I'd like to take a look at mine.

dloch
03-12-04, 06:20 PM
how are you reading the diagnostic codes on the car? I'd like to take a look at mine.Start the car or just turn the ignition to the on position first. Press the off and pass warmer buttons (of the Heat/cooling control) at the same time. All the segments of the IPC will light up and it will scroll through all the codes. It will say either current or history and the letters and numbers. You can get out by just shutting the ignition off.

jguelcher
03-13-04, 07:38 AM
There was a little left in the 2nd can. I had it hooked up for a good 10 minutes. That last bit just wouldn't go in.

zonie77
03-13-04, 10:49 AM
It appears the compressor is working. You feel the cold line. The computer does monitor some (all) of the AC operation but it's not giving you an error. You need to get gauges hooked up next. It could be something clogging the evaporator (Possibly the dead leaves if you park under a tree?)

I will advise you again to search some of the AC sites for more detailed info or help. Let us know what it turns out to be.