presto_z

iTrader: (12)

well my ac isnt blowing cold and im not sure why.. im trying to narrow it down (i tried the search but couldnt find much on this issue, just a bunch of deadend threads)...

it was working great yesterday but today just warm air (89* according to my pencil therm.)

i originally was hopeing it just needed to be recharged, but thought it was odd that it would just go from cold to warm overnight, but checked anyways.. it had 85psi (isnt that a little high?) on the low side (i dont have anything to check the psi on high side)

i made sure the compressor is kicking on and properly running through its cycles and it is

i thought the mixer door might be jammed but im pretty sure its not..

the metal lines are not getting cold or sweating at all, they are warm



is there any fuse that could cause this (fingers crossed)


any help would be great, i dont know to much about AC

thanks

98Camarod

iTrader: (43)

Have someone put some dye in it and see if there is a leak somewhere. I recharged mine and I had a ****** hole in the line that goes infront of the pulley, it burnt straight through it. I got freon every where. I didnt need any dye to figure that out. The guy I bought the car from said, "oh the a/c just needs a charge it quit at the end of the summer so I didnt worry about it." What a POS. It might just be an o-ring somewhere. If it was working the other day then I'd buy the freon with the dye in it and see how long it lasts.

PS It's been over a year and I still need that line

1998SilverZ28

I'm currently in an AC class under GM's ASEP program. I have done some AC work but I'm not very experienced in it. I'll lay down some of the conditions relating to high low side pressure (R-134a should have a pressure of 32psi)

Condition 1: Insufficient Cooling or No Cooling
Low side gauge: High pressure
High side gauge: Low pressure
A: Electrical or mechanical
I: Defective clutch
II: Defective compressor
-Valve plates
- Head gasket
- Broken piston ring

Condition 2: Insufficient Cooling
Low side gauge: High pressure
High side gauge: Normal pressure
1. Only found in TXV type systems
- Defective expansion valve (stuck in the open position)
I think you have an orifice tube system, so this one would not apply to you.

Condition 3: Insufficient or No cooling
Low side gauge: High pressure
High side gauge: High to extremely high pressure
A. Air in the system
- leak on low side and system goes into vacuum
- failure to evacuate system prior to charging (only applies if previous AC has been done, most often happens with "backyard mechanics" doing a "top off" charge". Also note that too much water/moisture in your AC system will turn the refrigerant into acid, in which case the condenser, compressor, evaporator and accumulator should be replaced, make sure that R-134a desiccant (moisture absorber XH7 or XH9) is used if the accumulator is replaced)
B. An overcharge of refrigerant
C. An overcharge of oil (PAG or POE for R-134a, Mineral Oil for R-12)
D. Condenser air passages clogged (either by debris or bent fins)
E. Defective cooling fan
F. An overheating engine
I think this is the most likely cause that fits you from what you described. Unfortunately, without actually being there and reading both high and low pressure gauges, it’s hard to diagnose an AC problem. But I hope this will help you out, good luck.

presto_z

iTrader: (12)

hey thanks alot.. a buddy of mine has a set of guages i can use so ill be going over there later on.. and the mechanic that works on all the trucks at work says he will look at it for me and let me know whats up tomorrow (no charge)

thanks alot and ill be sure to post up what the problem was

presto_z

iTrader: (12)

ok, the pressure on both the high and low is 100psi, im guessing thats bad that they are equaled out...

the compressor would kick on and the psi didnt change at all, and there is a little viewing window on his guage setup and it looked like there were little pieces of metal flake in the freon..


and now the compressor doesnt kick on at all


what now?

98Camarod

iTrader: (43)

I'm not an expert at a/c's or anything, but I do not believe it is good to run the a/c without any freon in it. I believe it has oil in it that lubricates everything.

presto_z

iTrader: (12)

well the compressor is shot... autozone wants 550 for a new one f that.. looks like im going on ebay and picking up a remanufactured one... anybody have badluck with um?

Havok2

iTrader: (118)

i got one in my blazer for 135 shipped. been good for montha and a half.

1998SilverZ28

Metal chunks in your refrigerant is bad bad bad. Chances are you have a reciprocating piston type compressor. Your compressor is basically like a small engine and probably what happened is the refrigerant should be in a gas state when the compressor is "pumping" it though the system. The refrigerant was probably in a liquid state and when it went through the compressor *BOOM* like hydro locking, blew up your piston(s) inside the compressor. If liquid refrigerant got into your compressor and you have an orifice tube system, it means your evaporator is not doing its job. I will give a short walk through of the states and pressers of the refrigerant starting at the compressor.

Compressor outlet: Pressure-High, refrigerant state-gas.
Condenser inlet/outlet: Pressure-High, State-gas to liquid.
Receiver/drier: Pressure- High, State- liquid (the receivers main purposes are to insure that only 100% liquid is feed to the metering device (orifice tube) and remove moisture from the system with desiccant)
Orifice tube: Pressure- High to low, State- liquid
Evaporator: Pressure- Low, State- Liquid to gas
Compressor inlet: Pressure- Low, State- gas

That’s how an orifice tube system should work. Basically a dealership fix of your car would include (at least) a new compressor, new orifice tube (this is because they are cheap and have a screen on them, if metal is in your system, this screen is blocked) and a new Receiver/drier (note that desiccant, used in the receiver/drier, is extremely hydroscopic, meaning it will absorb moisture from the air in an open AC system and should be replaced). It also wouldn’t be a bad idea to install an auxiliary filter in the line somewhere when the refrigerant is in the liquid state because of the metal in your system or you can flush out the system (if you elect to flush the system, use clean/new R-134a to flush it out, water can be used but must be completely dried out before reassembly of parts). If you do have this procedure done, be sure they/you add the correct amount and type of refrigerant oil in your system (R-134a uses PAG or POE type oil, PAG recommended. DO NOT use a mineral oil in your system, mineral oil was used in R-12 (R-12 aka Freon) systems and can not be used in an R-134a system). Also be sure they/you use either XH7 or XH9 desiccant. XH5 IS NOT compatible with R-134a. XH5 or lower is a desiccant used in R-12 systems and is not compatible. After you get all of this done, be sure to either replace or figure out why your evaporator is not fully evaporating the refrigerant from a liquid to a gas. This could be a mechanical problem or electrical ie: high/low side pressure sensors, hot/cold pressure sensors (usually only found on thermostatic expansion valve systems) or the compressor clutches not being turned on and off to cycle the refrigerant or stuck on. (on all the time is bad) It could also be faulty wiring, sensor(s) on the compressor or the module that controls the compressor.

Note: The above description is for an orifice tube system and not a thermostatic expansion valve system. R-134a systems should have a psi of 30-31 on the low side and a psi of 204-210 on the high side when operating normally.
Hope this will help you out on what you decide to do with your AC system. Good luck.

Edit: Also wanted to add in that a psi of 100 on the low and 100 on the high sounds like a block in the system. I think this would be the metal particles stuck in the screen on the orifice tube.

melchoir

iTrader: (4)

My AC just seems to take a little while before it blows cold, any ideas on that? =)

presto_z

iTrader: (12)

thanks 1998silverz28 it sounds like you know your ****

so i should replace the compressor (obviously) and the accumulator since its going to be open to hot humid florida air for a few hours..right?

what about the evap?

and what exactly is the orifice tube.. i know very little about ac systems

you have only 7 posts but youve shown that you know your stuff... thanks again

1998SilverZ28

Yes, personally I would recommend replacement of the compressor. Replacing the receiver/drier, especially since your down in Florida where it is not only hot but also humid (humidity and elevation have a huge impact on efficacy of the AC system by the way) is also a good idea. If your AC system is the orifice tube type, you only need to replace the receiver/drier because an orifice tube system does not have an accumulator. Accumulators are only found on a Thermal expansion valve (aka TXV) systems. Some orifice tube systems use a muffler to quiet the flow of refrigerant that may look very much like an accumulator but are not because these are usually placed in line before the condenser. I believe Chryslers use TXV systems the most, I do not think many GM cars use a TXV system.

The orifice tube is basically a small a piece of metal (installed in the line about 4-8 inches before the evaporator) that has a small hole in it. This small hole drops down the high pressure (because the compressor is still pushing the refrigerant) down to a low pressure so the refrigerant can evaporate properly in the evaporator and provide cool air to the cabin. The orifice tube has a screen on the inlet side (much like an oil pickup has a screen on it) and if you have metal in your system, this screen is likely clogged.

As for the evaporator, replacement may not be necessary. Diagnose why the evaporator may not be doing its job. If the evaporator is found to be bad, replace it. If an electrical fault is found to be the cause of the initial failure, fix that and replacement of the evaporator is not necessary. Installing a filter in the line or having the system flushed is a good idea in that case however, because you will still have excess metal in the lines and other parts.

As for melchoir and the taking awhile for the AC to kick on, on some systems this is normal. If it is excessively long however, the likely cause is probably an undercharge. If your system is undercharged, then you likely have a small leak in the ac system. The most cost effective way to find a leak in an AC system is to inject AC dye (compatible with the refrigerant in your system). Using a black light, the leak will appear to be greenish/yellow. The leak is likely at an o-ring seal or joint or at the condenser. Condensers leak often because of the small fins and are more susceptible to road debris as most condensers are mounted in front of the radiator. What ever the item or piece is that is leaking, replace it. I do not recommend "patching" an AC line especially on the high side if a line is found to be leaking. After that your system should be put into a vacuum (29Hg recommended) for at least 15-30 minutes, 4 hours is ideal (obviously dealerships and shops wont do 4 hours because time is money). This vacuum is applied for two reasons. The first is to help “pull in” refrigerant when it is charge. The second is because if any excess moisture is in the system it will boil out. Water can not exist in a vacuum. After the vacuum has been drawn for the proper amount of time, the pump should be shut off and the Hg monitored. As long as the Hg level stays at 20 Hg or higher for 5 minutes (mine usually end up around 22-23 Hg), it is within GM specs and the leak considered fixed. The system can then be charged.

MJK

iTrader: (3)

1998SilverZ28,

First thanks for your posts on this..I think all of us are learning a thing or two.

I know all shops vary but,what would you consider in your opinion a ball park figure as to a fair price a shop should charge for replacing a compressor,drier orifice tube,flush/vacuum?(Basically "the full deal").I'm talking labor because I'm sure that many of us would be able to source parts from different vendors/or used.

That way we have a decent idea as to wether a shop is trying rip people off or not.

Thanks!

presto_z

iTrader: (12)

QUESTION: do i need a special tool to remove the orifice tube?

1998SilverZ28

Well currently, I have not done that big of an AC job. The most I have done is replacement of the compressor and a condenser with a vacuum and recharge. I preformed it on a 2000 Grand Am or G6, don’t remember since they are basically the same thing. It was more of an expensive AC job because replacement of the compressor required dropping down the front cradle to remove the old compressor. If I recall correctly, replacement of the compressor paid 1.3 hours (on a scale of 1/10, one hour divided into tenths). The condenser is kind of a pain in the *** as well, that paid for almost 2 hours. The vacuum and recharge pays about an hour. My dealership charges at a rate of $89 an hour + parts.
So after all was said and done .4 (for diagnosis) + 1.3 + 2 + 1 = 3.7 X 89= $329.30
So I'm thinking replacing the receiver/drier would be about .7 labor and the orifice tube around .2 labor
so 4.6 X 89= $409.40 for labor + parts. Keep in mind, that’s the dealership price, so you get top quality work, but you also get a top quality work bill. The side ship would be less, but wither the quality would be the same, I don’t know. I would doubt it though because most side shops don’t have the quality AC machines that dealerships used and if at some point in time, someone put more refrigerant in their system say from autozone and it had stopleak in it. The machine becomes contaminated and it usually ends up doing more harm in your system than good.

MJK

iTrader: (3)

Thanks 1998SilverZ28!

Sorry for the slight thread jack presto_z

1998SilverZ28

For Presto_z, the answer to your question could be yes or no. In some systems, the orifice tube is press fitted or actually a part of the line leading from the receiver/drier. If this is the case, you can take the cheap route and just cut that piece of the line out and then patch in a new piece of the line with a new orifice tube installed. GM does not recommend this procedure. They recommend that the whole line leading from the receiver/drier be replaced or the old one be removed and converted into the new serviceable style. In other cases, the orifice tube can be removed with an orifice tube removal tool. To do this, remove the lower connection at the bottom of the evaporator. Lube the old orifice tube with PAG oil (helps to make it easier to remove) and insert the removal tool. Turn the T-handle of the tool slightly clockwise to engage the tool onto the tabs of the orifice tube. Then hold the T-handle portion of the tool and turn the outer sleeve or spool of the tool clockwise to remove the orifice tube. Do not turn the T-handle after it engages as this will break the orifice tube and make its removal more difficult. Since your car is a newer car, you should have the serviceable type orifice tube and will need the J-tool to remove it. You may be able to get lucky and find one at an auto parts store however.

presto_z

iTrader: (12)

ok.. to put the iceing on the cake my pass. side window motor has been dying but i never used it since i had ac, well now it barley creeps up and down since fl is getting into its 100* summers (i guess it doesnt like the heat). and my drivers side always wined a little bit, now it doesnt work at all, it trys to go down but it just goes "braaaaaa" and moves about a 1/4 inch...

i went to discount auto and picked up 2 motors they are 50 bucks a pop with a lifetime warrenty, so thats what ill be doing this weekend.. it looks like ill be driving the ol' LT1 for a few days (atleast it has ac lol)

presto_z

iTrader: (12)

well i still havnt ordered my compressor since ive been broke and driving my other camaro that has ac...

im replacing all the window motors in both cars since all are nearly dead.. i went to do the drivers side in my 01 and it was already replaced once befor which made it a breeze to replace, but the window stabalizer is broke so i have to wait for the new one to come in befor i put the door panel back on..

tomorrow im doing the other 3 so i should be a pro by the time im done lol
they are easier then most ppl say

presto_z

iTrader: (12)

im replacing the a/c components myself, and a friend of a friend works for an auto a/c shop and he is gonna pull the vacuum and charge it for me for pretty cheap

i stay away from the stealership at all cost

for instance the window guide with the felt was broken on mine, the dealership wanted 16, and a sponsor wanted only 7... so screw the dealerships