KNOWN ISSUE: A/C Wimps out on long runs
08-22-2015, 07:07 AM
#21
AudiWorld Super User
Thread Starter
Got some preliminary numbers off the thermometer this morning. When the four dash blowers ("AUTO") were used, 43F in the center dash vent. When three levels of vents were selected, that went up ten degrees. And, caused condensate on the outside of the windshield as well.
FWIW.
FWIW.
08-22-2015, 10:45 AM
#22
Audiworld Junior Member
I had a VW Tiguan before getting the Q5.
The Tiguan had AC problems, took it to the dealer and no luck. Nobody was able to find the problem after a couple visits.
The system would randomly fail, while driving as well as at idle in traffic etc.
Took it to an independent AC company. After many tests, changing cabin filter and still nothing.
Stumped! Living in a hot climate year round + leather seats you could imagine that AC is just a necessity.
So one day, I was cleaning inside my car with the AC on and the system failed. So I opened the bonnet, even though I'm not even sure what to look for. Looked around and one of the cooling fans had stopped working. But, it wasn't a complete failure because after some time it would resume and the AC would return. Sent the car back in, and told them the new information and they replaced the unit and never had trouble again.
So may be worth a look.
The Tiguan had AC problems, took it to the dealer and no luck. Nobody was able to find the problem after a couple visits.
The system would randomly fail, while driving as well as at idle in traffic etc.
Took it to an independent AC company. After many tests, changing cabin filter and still nothing.
Stumped! Living in a hot climate year round + leather seats you could imagine that AC is just a necessity.
So one day, I was cleaning inside my car with the AC on and the system failed. So I opened the bonnet, even though I'm not even sure what to look for. Looked around and one of the cooling fans had stopped working. But, it wasn't a complete failure because after some time it would resume and the AC would return. Sent the car back in, and told them the new information and they replaced the unit and never had trouble again.
So may be worth a look.
08-27-2015, 09:11 AM
#24
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I've only had this happen once, trip through the California desert from Phoenix to LA over Memorial Day weekend. Did make just one quick stop to let the dogs out, but kept the car running. The last 2-3 hours were BRUTAL -- felt like AC had completely quit working, nothing I tried really helped. It was hotter than normal through the desert that day, but not so hot that I would have thought it shouldn't work, normally days are much hotter here in Phoenix of course, only difference being that the engine nor AC was given a break for several hours. It hasn't recurred thankfully but I agree, definitely some sort of issue here that I haven't experienced with other cars.
08-27-2015, 11:15 AM
#25
AudiWorld Super User
Thread Starter
"I just completed a 10 hour trip in hot and humid weather (almost 90 degrees) with the thermostat on auto and had no issues. Must not be 100% of the time. "
You call that hot and humid weather? Mine didn't fail until nearly four hours with an outside temperature of (literally) 99.9F show on the dash, and (literally) 100% humidity from squalls, causing steam to rise off the highway and create a white-out just like a blizzard.
So no, no one says it is "all the time". But 90F is not considered unusually "hot" in much of the US. It happens every summer, even in New York and New England. We don't like it, but we routinely expect it. Which is why we buy cars with air conditioning. Which always [sic] deals with it.
I don't think Audi has the courage to acknowledge the problem, and without acknowledging it, they'll be unable to fix it. But I'm willing to be patient a little longer. When the carrot wilts, there's always a stick.
Better & cheaper for them to 'fess up and deal with it.
You call that hot and humid weather? Mine didn't fail until nearly four hours with an outside temperature of (literally) 99.9F show on the dash, and (literally) 100% humidity from squalls, causing steam to rise off the highway and create a white-out just like a blizzard.
So no, no one says it is "all the time". But 90F is not considered unusually "hot" in much of the US. It happens every summer, even in New York and New England. We don't like it, but we routinely expect it. Which is why we buy cars with air conditioning. Which always [sic] deals with it.
I don't think Audi has the courage to acknowledge the problem, and without acknowledging it, they'll be unable to fix it. But I'm willing to be patient a little longer. When the carrot wilts, there's always a stick.
Better & cheaper for them to 'fess up and deal with it.
08-27-2015, 03:53 PM
#26
"I just completed a 10 hour trip in hot and humid weather (almost 90 degrees) with the thermostat on auto and had no issues. Must not be 100% of the time. "
You call that hot and humid weather? Mine didn't fail until nearly four hours with an outside temperature of (literally) 99.9F show on the dash, and (literally) 100% humidity from squalls, causing steam to rise off the highway and create a white-out just like a blizzard.
So no, no one says it is "all the time". But 90F is not considered unusually "hot" in much of the US. It happens every summer, even in New York and New England. We don't like it, but we routinely expect it. Which is why we buy cars with air conditioning. Which always [sic] deals with it.
I don't think Audi has the courage to acknowledge the problem, and without acknowledging it, they'll be unable to fix it. But I'm willing to be patient a little longer. When the carrot wilts, there's always a stick.
Better & cheaper for them to 'fess up and deal with it.
You call that hot and humid weather? Mine didn't fail until nearly four hours with an outside temperature of (literally) 99.9F show on the dash, and (literally) 100% humidity from squalls, causing steam to rise off the highway and create a white-out just like a blizzard.
So no, no one says it is "all the time". But 90F is not considered unusually "hot" in much of the US. It happens every summer, even in New York and New England. We don't like it, but we routinely expect it. Which is why we buy cars with air conditioning. Which always [sic] deals with it.
I don't think Audi has the courage to acknowledge the problem, and without acknowledging it, they'll be unable to fix it. But I'm willing to be patient a little longer. When the carrot wilts, there's always a stick.
Better & cheaper for them to 'fess up and deal with it.
Did they find this TSB and check your A/C pressure switch? It is possible that you have a bad one and it is failing intermittently. That would shut down the compressor and cause it to blow warm air. It's a safety cutout on the high side and if it is flakey it may think the pressure is higher than it really is. It could re-set itself when the system cools down for a while as others have described. If the airflow is also being reduced, this may not have anything to do with it and the evaporator could be icing over? Just something to check
https://www.audiworld.com/forums/q5-.../#post24647052
08-27-2015, 04:52 PM
#27
AudiWorld Senior Member
Redd,
Did they find this TSB and check your A/C pressure switch? It is possible that you have a bad one and it is failing intermittently. That would shut down the compressor and cause it to blow warm air. It's a safety cutout on the high side and if it is flakey it may think the pressure is higher than it really is. It could re-set itself when the system cools down for a while as others have described. If the airflow is also being reduced, this may not have anything to do with it and the evaporator could be icing over? Just something to check
https://www.audiworld.com/forums/q5-.../#post24647052
Did they find this TSB and check your A/C pressure switch? It is possible that you have a bad one and it is failing intermittently. That would shut down the compressor and cause it to blow warm air. It's a safety cutout on the high side and if it is flakey it may think the pressure is higher than it really is. It could re-set itself when the system cools down for a while as others have described. If the airflow is also being reduced, this may not have anything to do with it and the evaporator could be icing over? Just something to check
https://www.audiworld.com/forums/q5-.../#post24647052
08-27-2015, 07:36 PM
#28
AudiWorld Super User
Thread Starter
I'd be surprised if they missed it, since they told me I wasn't the only customer with this problem, and that they'd run "all" tests and checks on it. But I can try to find out if they specifically did check.
I'd be surprised if I had a 2012 production sensor, in a late 2014 production car. Or if they missed something that obvious.
Wouldn't a low pressure condition throw an error code in the ODB systems? Or indicate in any way?
I'd be surprised if I had a 2012 production sensor, in a late 2014 production car. Or if they missed something that obvious.
Wouldn't a low pressure condition throw an error code in the ODB systems? Or indicate in any way?
08-28-2015, 04:26 AM
#29
I'd be surprised if they missed it, since they told me I wasn't the only customer with this problem, and that they'd run "all" tests and checks on it. But I can try to find out if they specifically did check.
I'd be surprised if I had a 2012 production sensor, in a late 2014 production car. Or if they missed something that obvious.
Wouldn't a low pressure condition throw an error code in the ODB systems? Or indicate in any way?
I'd be surprised if I had a 2012 production sensor, in a late 2014 production car. Or if they missed something that obvious.
Wouldn't a low pressure condition throw an error code in the ODB systems? Or indicate in any way?
08-28-2015, 10:48 AM
#30
AudiWorld Super User
Thread Starter
Spoke to the service manager today, he called me. Audi is VERY much aware there is an issue and has gotten repeat complaints from customers in our "subtropical" areas, from a number of dealerships.
They do believe we're all on the same drugs, ergh, I mean, that we all have found a problem which is real (G) and the tentative answer is that when the AC is on "AUTO" with a moderate temperature selected, there is a climate control computer which selects the fan speed, and then reduces that speed as the cabin gets down to the set temperature. But, they suspect, the computer may be ramping the fan speed (and the AC compressor) down at a rate which encourages the formation if ice crystals on the evaporator under certain humid conditions, leading to a total ice-up and failure.
The solution may be to replace the climate control computer, with one that has a different program in it.
This is logical. This is why we love computers. [Not.]
So I'm delighted to hear that Audi is taking this seriously, and that a new computer with new programming will be installed in my car, once it arrives and we an schedule a time for that. (Not just mine, they're going to replace a number of them to see if this works.)
And, incidentally, the low pressure switch was checked, that problem pre-dates my car's production date and is not an issue.
I must admit, the first time I got in my car (after a two week lapse) when the temperature had dropped from the high 80's to the low 60's, and the air conditioner (excuse me, climate control) magically greeted me with HEAT instead of cold air...I was thrilled.
In the last car, there was a four-position fan switch, a compressor switch, and a couple of bell cranks. Which did a perfectly fine job, my fingers knew exactly where they needed to go, even in the dark. No computer, no programs, no problems. Which is why I have zero tolerance for fancy computerized systems that bring their own new failure modes.
They do believe we're all on the same drugs, ergh, I mean, that we all have found a problem which is real (G) and the tentative answer is that when the AC is on "AUTO" with a moderate temperature selected, there is a climate control computer which selects the fan speed, and then reduces that speed as the cabin gets down to the set temperature. But, they suspect, the computer may be ramping the fan speed (and the AC compressor) down at a rate which encourages the formation if ice crystals on the evaporator under certain humid conditions, leading to a total ice-up and failure.
The solution may be to replace the climate control computer, with one that has a different program in it.
This is logical. This is why we love computers. [Not.]
So I'm delighted to hear that Audi is taking this seriously, and that a new computer with new programming will be installed in my car, once it arrives and we an schedule a time for that. (Not just mine, they're going to replace a number of them to see if this works.)
And, incidentally, the low pressure switch was checked, that problem pre-dates my car's production date and is not an issue.
I must admit, the first time I got in my car (after a two week lapse) when the temperature had dropped from the high 80's to the low 60's, and the air conditioner (excuse me, climate control) magically greeted me with HEAT instead of cold air...I was thrilled.
In the last car, there was a four-position fan switch, a compressor switch, and a couple of bell cranks. Which did a perfectly fine job, my fingers knew exactly where they needed to go, even in the dark. No computer, no programs, no problems. Which is why I have zero tolerance for fancy computerized systems that bring their own new failure modes.