tuffluck

iTrader: (4)

my condenser (maybe? the thing on the left side of the engine bay that is silver and behind the battery) is not getting that wet/cold when i turn my AC on lately. it comes and goes. sometimes it's fine and sometimes it's not cold at all, and sometimes it's mildly cold. does that mean that it has gone out and that's the only thing?

i had a leak in my line under the k member earlier this year thanks to firestone doing my alignment and bending that pipe down onto the k member. i wonder if that had anything to do with causing the condenser to fail? i have had the leak fixed since.

TooLateVTEC

iTrader: (2)

Well first you need to make sure it has the correct amount of R134a in it.

tuffluck

iTrader: (4)

it is not low.

intense3123

First, that's the accumulator, not the condenser. Condenser is located in front of the radiator.

How was your leak fixed?

Also, for future knowledge, left and right is as you're sitting in the car. So the battery and accumulator would be on the right side.

tuffluck

iTrader: (4)

okay, the metal shiny thing on the right side. the leak was fixed by being welded. the part was nowhere to be found (GM has discontinued it) so the weld was the only thing possible.

the weld made the system hold a vacuum and the system was recharged to its full capacity. the AC is now back to normal (so no freon is leaking for sure), but this is the 2nd time the accumulator has felt not cold and a resulting luke warm AC ensued. the fact that it comes back around in full swing a day or two later really confuses me.

any ideas?

fleetmgr

Are you seeing frost anywhere else, like near the welded area? If not, then I'd say that you are lacking refrigerant. The fact that it was charged at some point in the past doesn't have much bearing on what it's doing now, no matter how recently it was done.

tuffluck

iTrader: (4)

it was only warm for a day, then back to freezing cold like before. it is freezing cold now and i haven't done a thing. so it cannot be a lack of refrigerant.

LS6427

iTrader: (2)

Could have a blockage. Or maybe the compressor is turning on and off, but staying off longer each time. Might want to have the electrical wire that plugs into the compressor checked to see if its frayed or melted, etc. I did have that wire replaced on mine some years ago because it was frayed and my compressor was shutting off and staying off, then it would stay on for awhile, then stop for good again. Very simple and fast fix too.


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fleetmgr

OK, as it comes and goes...I agree with the blockage idea. This may cost a bit, but:

Take it to a shop and have the refrigerant recovered - and have them evacuate it and hold vacuum for several hours.

If moisture has somehow gotten into the system, it will form an ice plug at the outlet of the orifice tube. When it forms, no A/C. When it melts, A/C works again. Instant intermittent problem.

tuffluck

iTrader: (4)

where is the plug--it just goes straight into the condensor on the right side of the engine?

i really am doubting the ice blockage thing because in dallas this summer the average temp has been over 100 every day, and i have left the thing sitting overnight and the next day it still didn't blow cold air the entire day (the last time this happened). i would certainly think ice would melt within 2 minutes out here in this heat.

could it be something else that blocks it? considering it has happened twice that seems possible, but considering it hasn't happened in a while, whatever was blocking it seems also like it could have passed through already?

fleetmgr

The ice is INSIDE the lines, normally at the exit of the orifice tube (or, at the exit of whatever a vehicle uses for the same function). You're right, it will melt within a couple of minutes of the car being shut off, but as soon as you start the car and turn the air on, it re-forms. This is because nothing has been done to remove the moisture from the system in the first place, so there isn't any way for it not to re-freeze in the same place. And we aren't talking about much in the way of moisture...maybe only enough to make one drop of water if you froze it all. It also doesn't have to completely block off the orifice tube to cause what you are seeing, it only has to restrict the flow of refrigerant into the evaporator and thereby significantly reduce overall system cooling capacity.

The refrigerant temperature at the exit of the orifice tube will be about 20 degrees F assuming a temperature of 40 degrees F for the air coming out of your A/C vents in the car.

tuffluck

iTrader: (4)

i get you. well i guess then i find it strange it does it so infrequently though. and as well, there was about a 15 minute vacuum pulled on my system back in april when the hole was fixed. the AC guy said he did not like to pull a vacuum for a long time on an older system (over 5 years) because there is a good possibility you can cause a problem in the system by putting it under so much pressure.

fleetmgr

15 minutes isn't enough time to leave the vacuum on to do any real good. I recommend at least 2 hrs, 4 is better. The reason is the moisture can become entrained in the oil, which circulates throughout the system. This is why you see it intermittently. Getting the moisture out of the oil takes time. We aren't talking about anything approaching water drops in size here, more like water vapor.

Your mechanics thought about not having the vacuum on for very long is misguided at best. If it causes a problem, then the problem pre-existed and needed to be fixed anyway.

This is my procedure for evacuating a system:

1. After reparing all known problems, pull a vacuum of at least 29.5" Hg and hold for 2-4 hrs.
2. Break vacuum with refrigerant to 0 psi.
3. Re-establish vacuum to at least 29.5" Hg and hold for 30 minutes. The reason you break vacuum with refrigerant is it will "sweep" anything remaining in the system.
4. Recharge system with the specified amount of refrigerant.
5. Recheck the sytem for leaks using an electronic detector, not using dye. The dye works over time, but in the meantime you could be undoing all that you just did, especially if the leak is on the suction side of the compressor. The suction side could be operating in a vacuum under the right conditions, so now you're sucking air/moisture back into the system. The electronic detectors will also show a leak right away that you might not see for a long time with dye. The detectors can pick up a leak as small as one ounce per year. However, they aren't as fast/convenient to use...you actually have to do some work with them as opposed to charging the system and sending you out the door for a few days, and then coming back to see where the dye has shown up. Also, then the shop can't charge you for another can of refrigerant. :-)