I have a 2007 Audi A6 3.2. The a/c is usually very cold. The other day I took the car on a 1 1/2 hr ride and no issues. On the way back the a/c was not working properly, I had to put the recirculate on to cool the car. In the 8 years owning this car I never used recirculate even on 100 degree days. Today on a short trip a/c was fine, it appears when a/c is on a long time it isnt cooling properly, does system need a recharge, it has never been touched or is something else going on here.
a/c issue
- Thread starter raaizin
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Has is blown warm again or just that once? Could something have been blocking the outside air intake when it went warm?
I'd be tempted to have someone like a Valvoline Instant oil lube location check & recharge the system if it was my car.
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The AC might need a small charge. If the AC is a little low the part that gets cold, evaporator, might get too cold and form ice. The ice blocks the flow of air into the cabin. AC gauges would be used to diagnose the problem. If you don't have gauges try the following. The next time it does not blow cold after being used put the selector on vent. If after a few minutes it begins to blow cold with the AC off that would mean the ice buildup is melting and air is flowing through the evaporator and being cooled by the residual ice.
Rule out the usual stuff. Is it a blend door malfunction so that hot air is getting blended in? Are the pressures (high/low) normal when this happens?
If it really is related to the AC system and not a control problem, it may be moisture contamination,although its hard to imagine if the system hasn't been opened or recharged. All systems have at least a tiny amount of moisture, but the dessicant in the drier (or accumulator, depending on whether its located on the high or low side) is supposed to capture stray moisture and hold it safely out of circulation. Long periods of operation with a loaded drier can force it to release a little moisture, which can then freeze in the expansion valve or orifice valve. Next short trip, the frozen moisture is gone and re-captured by the dessicant. But if its an accumulator type system (dessicant on the low pressure/cold side) its less likely to do that.
If it really is related to the AC system and not a control problem, it may be moisture contamination,although its hard to imagine if the system hasn't been opened or recharged. All systems have at least a tiny amount of moisture, but the dessicant in the drier (or accumulator, depending on whether its located on the high or low side) is supposed to capture stray moisture and hold it safely out of circulation. Long periods of operation with a loaded drier can force it to release a little moisture, which can then freeze in the expansion valve or orifice valve. Next short trip, the frozen moisture is gone and re-captured by the dessicant. But if its an accumulator type system (dessicant on the low pressure/cold side) its less likely to do that.
Its due for a recharge.no system is perfectly sealed and some loss over 8 yrs is normal.have it done correctly with a shop that has an ac machine.
Most likely you will be suprized at how well it will work since your used to it now.
Most likely you will be suprized at how well it will work since your used to it now.
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I agree with Chris, most if not all systems loose some in 5-10 years. Every few years I recharged my 3-4 cars with 1 shared can of 10-12 oz.
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Drop an oil charge in the system.
http://www.walmart.com/ip/PAG-100-with-ICE-32-Oil-Charge/16888788
Contains one ounce PAG 100 oil, one ounce R134a, and one ounce "Performance Enhancer"
Do this ONCE, the system will drown....
Just did my 2002 this summer, nice and cold...
http://www.walmart.com/ip/PAG-100-with-ICE-32-Oil-Charge/16888788
Contains one ounce PAG 100 oil, one ounce R134a, and one ounce "Performance Enhancer"
Do this ONCE, the system will drown....
Just did my 2002 this summer, nice and cold...
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Originally Posted By: mattwithcats
Drop an oil charge in the system.
http://www.walmart.com/ip/PAG-100-with-ICE-32-Oil-Charge/16888788
Contains one ounce PAG 100 oil, one ounce R134a, and one ounce "Performance Enhancer"
Do this ONCE, the system will drown....
Just did my 2002 this summer, nice and cold...
That's a great way to ruin the compressor...
Drop an oil charge in the system.
http://www.walmart.com/ip/PAG-100-with-ICE-32-Oil-Charge/16888788
Contains one ounce PAG 100 oil, one ounce R134a, and one ounce "Performance Enhancer"
Do this ONCE, the system will drown....
Just did my 2002 this summer, nice and cold...
That's a great way to ruin the compressor...
Originally Posted By: skyactiv
I'd be tempted to have someone like a Valvoline Instant oil lube location check & recharge the system if it was my car.
LOL....I wouldn't have those people anywhere near my Audi, even for an oil change.
As for charging the system, it could need a SMALL top up, as over time a small amount of refrigerant will be able to escape the system, unless you have a large leak, or can see PAG oil dripping from a leak in the system DO NOT ADD OIL!
I'd be tempted to have someone like a Valvoline Instant oil lube location check & recharge the system if it was my car.
LOL....I wouldn't have those people anywhere near my Audi, even for an oil change.
As for charging the system, it could need a SMALL top up, as over time a small amount of refrigerant will be able to escape the system, unless you have a large leak, or can see PAG oil dripping from a leak in the system DO NOT ADD OIL!
Ever put a cabin air filter in it?
Ever put a cabin air filter in it?
The leak is likely to get worse over time as rubber o-rigs or other seals dry out. The system is 100% sealed and should not leak any R134a unless there is a component that is leaking. Which is bound to happen after many years. The proper way is to have a shop find the leak and fix it, then refill the system by weight. Many people dump in a can of R134a and call it a day.
The proper way to add R134a is to have manifold gauges for both high and low pressure. That can do a decent job but the proper way is always to evacuate the system and fill be weight.
Never never add leak stop or R134a with leak stop.
If you add R134a yourself, make sure you purge the hoses of air before opening the can of R134a.
The proper way to add R134a is to have manifold gauges for both high and low pressure. That can do a decent job but the proper way is always to evacuate the system and fill be weight.
Never never add leak stop or R134a with leak stop.
If you add R134a yourself, make sure you purge the hoses of air before opening the can of R134a.
Originally Posted By: Donald
The leak is likely to get worse over time as rubber o-rigs or other seals dry out. The system is 100% sealed and should not leak any R134a unless there is a component that is leaking.
I disagree- a home refrigerator or window air-conditioner is "100% sealed" with a hermetic compressor and soldered or brazed copper fittings. No automotive system is hermetic- they all have a shaft seal at the compressor as well as O-rings at hose junctions, and all shaft seals will leak a small amount of gas from the day they're put in service. It should be a *tiny* loss, but its present and inevitable, and since they've been reducing the total charge volume of car A/C systems in recent years, it can become noticeable in 5 years or so, whereas the old systems with 1.5-2 pounds of refrigerant could go a lot longer before the loss becomes noticeable in performance. So long as a system has a volume of liquid refrigerant in the bottom of the condenser and the liquid line leading to the orifice in normal operation, you won't notice a problem... but the instant that the liquid volume gets low enough that gas bubbles start hitting the expansion point, you begin to lose performance. The old systems had a receiver/drier that stayed full of liquid- as much as a couple of pints worth- so that level could slowly fall for years before it showed up as a problem.
The leak is likely to get worse over time as rubber o-rigs or other seals dry out. The system is 100% sealed and should not leak any R134a unless there is a component that is leaking.
I disagree- a home refrigerator or window air-conditioner is "100% sealed" with a hermetic compressor and soldered or brazed copper fittings. No automotive system is hermetic- they all have a shaft seal at the compressor as well as O-rings at hose junctions, and all shaft seals will leak a small amount of gas from the day they're put in service. It should be a *tiny* loss, but its present and inevitable, and since they've been reducing the total charge volume of car A/C systems in recent years, it can become noticeable in 5 years or so, whereas the old systems with 1.5-2 pounds of refrigerant could go a lot longer before the loss becomes noticeable in performance. So long as a system has a volume of liquid refrigerant in the bottom of the condenser and the liquid line leading to the orifice in normal operation, you won't notice a problem... but the instant that the liquid volume gets low enough that gas bubbles start hitting the expansion point, you begin to lose performance. The old systems had a receiver/drier that stayed full of liquid- as much as a couple of pints worth- so that level could slowly fall for years before it showed up as a problem.
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