help me with ac (hehe, it rhymes) :-)

turboken

Registered User
my air conditioner works decent (froze me out on 65 degrees at a little over 75 degrees outside), but it WILL NOT WORK CORRECTLY if it is sitting. after about 20 seconds, it makes a screaming sound, as if the compressor was locking up. it also shoots oil out of the compressor (out of the thing that looks like a pressure relief;if looking straight at the ac compressor from the front, the valve points at about 10:00ish), which hits the air intake tube and drips onto the motor. Its soo bad that the first time i heard it, i felt my heart go into my throat, and I ran and dove thru the open window to shut the car off.

my hypothesis is that for some reason, it overheats without air passing over the ac coils in front of the radiator. anyone else have this prob or any input? thanks guys.

ken
 
He is right, r12 - r134 work of preasure and temp drop, without the fan the preasure just keeps bulding. You need to make sure that the fan is working. Try using a paper clip to pull the codes in the computer.... This will make the fan so you can get a start on figuring it out.

Let us know what you find.

Tim
 
Overcharged?

What is your high-side pressure and is this a retrofit to R-134a? Radiator fan should come on in high speed when A/C is turned on so that's real easy to check. It is unlikely that the relief valve would lift that quickly on a properly charged system, even if the fan wasn't working. Setpoint is in the 350-400 psig range and you shouldn't be seeing anything much above 250 psig. A/C performance usually suffers first, when there is a lack of air flow over the condenser. You'd also see engine temp rise anytime you were sitting stationary for any appreciable period of time. if the fan wasn't working at all. Once you lift that relief, it is likely to be a source of leakage in the future (can check with Snoop or soapy water). Not sure if valve can be replaced separately (GM's can) and might require a new suction/discharge hose assy. I've never had one lift so I've never had to look. If you retrofitted to R-134a, the charge should have been approximately 80% of the R-12 charge or 2.4 x Ambient temperature, for the high-side pressure, if gages are used. A/C work is best done right the first time as there are no short-cuts.
 
38SCPROJECT said:
There also could be a blockage in the high side line tooo
I'll second that, bet the O-tube is blocked.. Also 65deg on a 75deg day... is poor performance. Check the fan first, then get a pressure reading on the high side.. that valve is a blow off valve designed to relieve overpressure.
 
thanks guys, ill check it out this weekend. thats the crazy thing, it works fine. it got too cold I had to turn it off the other day.
 
65 Degrees?

Is that 65 Degrees F at the vents or is that average temperature for the passenger compartment? 65 Degrees at the vents wouldn't freeze anyone out and is poor performance. One would expect 20-30 degree drop under outside ambient temperature minimum in a properly functioning system. A blocked Orifice tube is more than likely an indication of more ominous things to come, like total compressor failure and the infamous "Black Death" contamination. Can you rotate (clockwise) the compressor by the clutch (front face of the pulley) by hand? If not, your compressor is probably on its way out. A high charge can also make the compressor hard to turn. Sources for internal contamination this sealed system are few, compressor seals/internals and the dessicant located in the accumulator. A set of good gauges is a must for diagnosing problems. Even a cheap single gauge with adapters is better than nothing. With a set a gauges, a blocked orifice tube would indicated by a low Low Pressure reading, along with a high High Pressure reading.
 
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The ECC is just like my turbocoupe. 65 is the setting on the digital panel. 60 is full cold all the time. 65, with the fan setting on auto will cool the car to 65 degrees, then shut off (an on and offf to regulate). It gets COLD, and I had to turn it up to 75 because i was cold. If it sits still, it isn't as cold and it will "leak oil". It's either oil or freeon, because it evaporates within 20 mins. thanks guys, ill try and figure it out.
 
"Black Death"

“Black Death” is the term coined by the A/C industry to describe the black gritty spoo that results from teflon & aluminum wear particles, refrigerant oil and the heat generated when a Ford FX15 compressor (or GM DA6) STB. A lot of this stuff will get stopped between the compressor discharge and the filter screen of the Orifice Tube. This includes the condenser, which is between the compressor and liquid line, in the flow path. Some of it may still get by and deposit in the evaporator and accumulator. General consensus is to replace everything except the evaporator and flush the heck out of the evaporator. Condenser can be flushed but if you have a parallel flow condenser that can be a time consuming event. Suction/Discharge line can be flushed as well. All of this S*** must be removed or you are looking at a repeat performance in the not to distant future. Use something like a coffee filter to check results. Compressor, Accumulator and Liquid line (where O-tube is) are musts for replacement. Most of us have FX15 compressors, some have FS10’s which are better and preferable as replacements. Better to buy a new one than get a rebuilt as most rebuilds are POS’ and the difference in price isn’t that much. BTW, if you are leaking oil, you are also leaking refrigerant as they basically dissolve in each other and come out together. Refrigerant then escapes to the atmosphere, leaving the oil behind. That’s why your spring-lok connections may look oily and gritty.
 
I have an 89 that I bought with bad AC

Should I just try changing the accumulator and o-rings then flush the system before a recharge?

I priced out new parts (accumulator, compressor, condenser, discharge/suction lines) at almost $600. I don't really want to spend that to get the AC working.


Aaron
 
The Big Picture, don't fall asleep

If you can turn the compressor over by hand, it may be OK. Besides the O-Rings and Accumulator, you should replace the Liquid Line/Orifice Tube too. That should run you $20-$35. If everything else checks out, you should be able to reuse the compressor, condenser and Suction/Discharge line. After removing it, I would cut the metal part of the Liquid Line, near the crimp as that’s where the O-Tube is. Preferably, use a tubing cutter and after removing paint (if painted), from the cut area. Inspect the O-Tube filter for debris. If it is clean, things are looking good. If you see black stuff accumulated there, your compressor is on its way out and will have to be replaced (paint was removed so it wouldn’t get on the filter while cutting). Obviously, everything except the Evaporator has to be removed. Flush the compressor with the refrigerant oil that you’ll be using by pouring some in the suction and turning the compressor by hand until oil comes out the discharge. Check for debris and repeat a few times to ensure old oil is removed. DO NOT use solvent on the compressor. Condenser, Evaporator and Suction/Discharge line can be flushed with a highly volatile solvent such as Lacquer Thinner or some places sell A/C system flush. Chase with dry compressed air, Pros use nitrogen but most of use are lucky to have compressed air. Evaporator will be bit of a pain, as you’ll smell solvent long after you stop getting liquid solvent out. After blowing air through the condenser, set it out in the sun to help vaporize any remaining solvent. The system takes about 8oz of refrigerant oil. Distribute it as 2oz each to the compressor, condenser, accumulator and evaporator. Reassemble the system using new O-Rings and try to get something called Nylog. It as about $5 a bottle and has been called “Snot in a Bottle” and use it on all of the rings prior to making the connection. It helps prevent leaks and keeps rings from drying out. Now you’re ready to pull vacuum. If you can get your hands on a vacuum pump, leave the radiator out. I use a 1000-watt quartz lamp to add a little heat to the condenser while pulling the system down. The warmer it is, the easier it is to remove the moisture in the system. Pull vacuum for at least 45 minutes. If you don’t have access to a pump put the rad back in and take the car to a shop and let them evacuate the system. If vacuum holds, you may still be OK but vacuum is only a 15 psi differential in pressure and not the preferred method for checking for leaks. When running, pressures will be around 200 psig or more on the high side. Now you should be ready to add refrigerant. There are quite a few choices out so I won’t go into the directions for charging because some are charged as liquids and others as gas. Choose your refrigerant oil based on what refrigerant you want to use. They must be compatible or the compressor is TOAST. Also, if you’re getting a new accumulator make sure that it’s sealed tightly. Don’t unseal until you’re ready to install. If it doesn’t “pop” when you unseal it, air has leaked in and more than likely saturated the desiccant. TAKE IT BACK! Water is the enemy here and we need to keep it out. I’ve gotten a few from AZ Mobile Air (www.ackits.com) and they’re sealed pretty well. I won’t go into details on the one I got from AutoZone. Others may say they did a lot less to get their A/C going again but chances are that if you don't do it right the first time, you'll be doing it again later.
 
I dont know if someone covered it ,but is there a chance that the pressure switch in the accumulator is malfunctioning?
 
Jim Cook is precisely correct. Guess he spent a little time at the ac bulliten board ;) These are the same guidelines I'd give. I replaced/retro'd my A/C last summer based on info from here and the A/C board and just 2 days ago, I was getting 28 deg vent temps on a 75 deg day. Normally, temps that low would cause an evap freeze up but with low humidity, its achievable.
I'd add one other note and that is that an aftermarket condenser (serpentine or parallel flow) will outperform the OEM dual pass tube-and-fin design and yield better r134a cooling.
OK.. and a second note. I used all NEW AZone parts: Factory Air FS10 compressor, GoDan condenser, Factory Air evaporator, Don't-recall accumulator, and liquid line w/Otube. Only part which was reusable was the suction/discharge line+manifold which I flushed with brake parts cleaner. Used PAG in the inside and mineral oil on the Orings (didn't have any Nylog at the time). Had the system vaccuumed and charged with 32oz of r134a (80% of the original 40oz of r12).
I advise staying away from the cheapo $30 retro death kits; you contaminate the system [bad air in] and possibly overcharge it. :)
 
Yep! Been There and done that

I spent a lot of time surfing the aircondition.com website back in 2001 (a few others as well). Mostly, because they used to have a forum for alternate refrigerants and I was trying learn about R-12 replacements. A few guys there (professionals taking the time out to help us DIYers) really know their stuff. Same questions come up over and over again so you shouldn't have to look too hard to find someone with the same problem as you. You might not like the answers (more work and $$) but they know what they're talking about. I ended up buying a lot of stuff from Tim @ AZ Mobile Air, compressors, accumulators, condensers and POE oil (Texaco HFC 100). Tim used to have a new compressor for the SC, part # 6-3016NSP from SPI that was under $250. Vacuum pump, gauges, tools and other service parts, including Nylog and PAO oil, I got from Warren at ACSource.com. Also took the time to get the 609 Cert online, it's an open book test and not hard at all (or expensive) if you read the training manual at least once. With a 609 certification, you can buy R-12 even if it is up there in price. It is coming down a bit though as the number of vehicles using it continues to decline. This is a hobby for me and I'm no expert by any stretch but I do have two SC's with icebox cold A/C. Also sitting on about 50lb of r-12, 80lb of r-134a, 30lb of ES-12a and 25lb of Autofrost (R406a) so I'm all set for the forseeable future. BTW, I ruled out AutoZone as a source for A/C parts when they tried to sell me an expansion valve instead of a Liquid Line/Orifice Tube (just because their computer said so) and an accumulator that wasn't sealed properly.
 
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