A/C stops blowing after 45 minutes or so
#1
A/C stops blowing after 45 minutes or so
Having a weird issue with the AC in my car, on long drives. Car is a 2007 Acura TL (climate control system).
I first noticed this late last summer, but put it off. What happens is, after 45-60 minutes of driving, the AC starts to get weaker. The air coming out starts getting less cool, then eventually just stops blowing almost entirely, despite the cabin heating up - it's not just slowing down because the temperature is reached.
Also, after driving for awhile, while the AC still blows cold, there's some fog/mist/vapor coming from the vents, and shortly after, the AC starts to die.
This is in auto mode, but then overriding the controls, and for example, manually setting fan to high speed, air (warm or cold) simply doesn't come out of the vents. I can hear something that sounds like a fan blowing inside the dash or the engine bay, but nothing's coming out of the vents.
Where should I start with troubleshooting this? From doing some research, sounds like maybe the blower motor resistor?
Never had any similar issue with the heat in the winter.
I first noticed this late last summer, but put it off. What happens is, after 45-60 minutes of driving, the AC starts to get weaker. The air coming out starts getting less cool, then eventually just stops blowing almost entirely, despite the cabin heating up - it's not just slowing down because the temperature is reached.
Also, after driving for awhile, while the AC still blows cold, there's some fog/mist/vapor coming from the vents, and shortly after, the AC starts to die.
This is in auto mode, but then overriding the controls, and for example, manually setting fan to high speed, air (warm or cold) simply doesn't come out of the vents. I can hear something that sounds like a fan blowing inside the dash or the engine bay, but nothing's coming out of the vents.
Where should I start with troubleshooting this? From doing some research, sounds like maybe the blower motor resistor?
Never had any similar issue with the heat in the winter.
Last edited by stm25rs; 06-19-2017 at 12:09 PM.
#2
Blower motor resistor would be at fault if you couldn't change the speed. You're able to change the speed because you can hear it right? I am having the exact same issue. It's ice cold then after 20 mins it will stop cooling so much and I am getting the vapor as well with the lack of air coming out the vents. I also get the expansion valve hiss very faintly inbetween too (should not hear that constantly) . My previous 06 was too cold. I was going to do a full vacuum and recharge when I had some time but been so busy, I have a feeling we may be low. I am also going to check the cabin filter regarding lack of flow.
Last edited by WDPanda; 06-19-2017 at 03:25 PM.
#4
Pro
My car does the same thing, its the evap freezing and not letting the air pass over it, thats why you can adjust and hear the fan but nothing comes out. On mine if I turn the fan to high little pieces of ice come out.
#6
Suzuka Master
iTrader: (1)
^ Need to put gauges on the system to see charge. If appropriate need to check other items e.g. heater control valve, doors.
Also, evap freezing could possibly from a low charge, but have seen the evap freeze when charge is up to snuff and high humidity, so one can try to run on recirculate. Not certain as to what Acura has installed to prevent freezing.
Many years ago purchased a RX7 that had most of the a/c missing, did an install and when completed drove maybe 30 minutes and frost started coming out of the vents. Installed an evaporator temp sensor in line and this solved the problem, but I would think most modern vehicles sould have some type of sensor built in????
Also, evap freezing could possibly from a low charge, but have seen the evap freeze when charge is up to snuff and high humidity, so one can try to run on recirculate. Not certain as to what Acura has installed to prevent freezing.
Many years ago purchased a RX7 that had most of the a/c missing, did an install and when completed drove maybe 30 minutes and frost started coming out of the vents. Installed an evaporator temp sensor in line and this solved the problem, but I would think most modern vehicles sould have some type of sensor built in????
Last edited by Turbonut; 06-20-2017 at 04:04 PM.
#7
Pro
Also, evap freezing could possibly from a low charge, but have seen the evap freeze when charge is up to snuff and high humidity, so one can try to run on recirculate. Not certain as to what Acura has installed to prevent freezing.
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#8
check your ac clutch relay. They were known to be bad. they will stick on causing your ac compressor to keep running which may be causing your evaporator to freeze up. I believe there are a couple relays that are the same in there so you could switch them around and see if the problem is any better.
#9
Drifting
When the AC works normal and then turns warm with the lines at or around the expansion valve freezing up is an indication of too much moisture in the AC system. You may have a leak or some how introduced moisture while adding freon the wrong way.
The solution is to remove the moisture from the AC lines.
Evacuate the freon from the system and hold the system under constan vacuum for a minimum of half hour. Water will boil under vacuum so the vacuum machine will suck the water vapors out of the ac system.
Then just add the appropriate amount of freon and oil without introducing air back into the ac system.
Note, you should replace the dryer prior to sucking down the ac system.
The solution is to remove the moisture from the AC lines.
Evacuate the freon from the system and hold the system under constan vacuum for a minimum of half hour. Water will boil under vacuum so the vacuum machine will suck the water vapors out of the ac system.
Then just add the appropriate amount of freon and oil without introducing air back into the ac system.
Note, you should replace the dryer prior to sucking down the ac system.
#10
Suzuka Master
iTrader: (1)
Did find in the OEM parts:
80560-SDN-A01 A/C Thermistor $28.23 $21.17
Evaporator Temp Sensor Test
Remove sensor and dip in ice water and measure resistance between its terminals. Then pour warm water and check change in resistance. Compare changes.
Resistance at 32 degrees 30, 80 degrees 8.
If not in range, replace.
My scanner not working so maybe someone can scan pg 1444 FSM Section 21-66
Here's the manual, then go to the section:
http://www.nnstudios.com/azine/Acura%20TL%202004-2007%20Service%20Manual.pdf
80560-SDN-A01 A/C Thermistor $28.23 $21.17
Evaporator Temp Sensor Test
Remove sensor and dip in ice water and measure resistance between its terminals. Then pour warm water and check change in resistance. Compare changes.
Resistance at 32 degrees 30, 80 degrees 8.
If not in range, replace.
My scanner not working so maybe someone can scan pg 1444 FSM Section 21-66
Here's the manual, then go to the section:
http://www.nnstudios.com/azine/Acura%20TL%202004-2007%20Service%20Manual.pdf
Last edited by Turbonut; 06-22-2017 at 06:21 AM.
#11
I seem to only have this issue when it's extremely hot and humid. I also leave my window down time to time to get fresh outside air vs the moldy goodness. In temps below extremely hot, it works like a charm all day long. Will have to do more testing.
#12
Thanks for the responses.
Also dealing with this at the moment:
https://acurazine.com/forums/3g-tl-p.../#post16053007
Asked the shop to check out my AC, and they said they think it's the compressor....
Also dealing with this at the moment:
https://acurazine.com/forums/3g-tl-p.../#post16053007
Asked the shop to check out my AC, and they said they think it's the compressor....
#13
Pro
Took my car in today to get the A/C checked. Turns out it was low on freon, performed A/C service and put dye to see if it leaks, its for sure colder now, we will see if it freezes anymore.
BTW, Springfield, MO Acura labor rate is now $124.95, damn!!
BTW, Springfield, MO Acura labor rate is now $124.95, damn!!
#14
Mine was low on refrigerant, so they vac'd it down and recharged the system. Said the vent is now blowing at 32 degrees! Which the tech says is actually abnormally cold, still doing some testing, but said might be the evap temp sensor and/or low side pressure switch.
#16
My 2006 TL AC works great and will freeze you out for about 3-4 hours, then the amount of air-flow from the vents will decrease to almost nothing, but the air is still very cold.
will replace the cabin filter and the temperature senor in the upcoming days and post the results. From other's I believe the sensor is the problem. I can accomplish these two tasks easily, if my back holds out. I hate under dash work!
will replace the cabin filter and the temperature senor in the upcoming days and post the results. From other's I believe the sensor is the problem. I can accomplish these two tasks easily, if my back holds out. I hate under dash work!
Last edited by youraway; 07-13-2017 at 02:24 PM. Reason: spelling errors
#17
check your ac clutch relay. They were known to be bad. they will stick on causing your ac compressor to keep running which may be causing your evaporator to freeze up. I believe there are a couple relays that are the same in there so you could switch them around and see if the problem is any better.
#18
My 2006 TL AC works great and will freeze you out for about 3-4 hours, then the amount of air-flow from the vents will decrease to almost nothing, but the air is still very cold.
will replace the cabin filter and the temperature senor in the upcoming days and post the results. From other's I believe the sensor is the problem. I can accomplish these two tasks easily, if my back holds out. I hate under dash work!
will replace the cabin filter and the temperature senor in the upcoming days and post the results. From other's I believe the sensor is the problem. I can accomplish these two tasks easily, if my back holds out. I hate under dash work!
#19
Per my other thread:
https://acurazine.com/forums/3g-tl-p.../#post16053007
I'm done with this shop. They couldn't properly diagnose my battery drain problem. Initially said my new autozone (or advance auto or whatever) battery was dead, and replaced it, then when that was dying they claimed it was a bad fuel injector ECU, and resetting the ECU fixed it. I got the bar back, battery started dying again, and I decided to replace the AC compressor clutch relay (which I had specifically emailed them info on and asked to test), and boom, battery drain is done.
Drove the car about 50 minutes, twice, over the weekend, and AC stayed cold.
Was some mist coming from the driver's side vent at some points, but it was also very hot and humid while I was driving.
Been meaning to replace my cabin filter anyway - have had the car for about 3 years and haven't replaced it yet.
https://acurazine.com/forums/3g-tl-p.../#post16053007
I'm done with this shop. They couldn't properly diagnose my battery drain problem. Initially said my new autozone (or advance auto or whatever) battery was dead, and replaced it, then when that was dying they claimed it was a bad fuel injector ECU, and resetting the ECU fixed it. I got the bar back, battery started dying again, and I decided to replace the AC compressor clutch relay (which I had specifically emailed them info on and asked to test), and boom, battery drain is done.
Drove the car about 50 minutes, twice, over the weekend, and AC stayed cold.
Was some mist coming from the driver's side vent at some points, but it was also very hot and humid while I was driving.
Been meaning to replace my cabin filter anyway - have had the car for about 3 years and haven't replaced it yet.
#20
I had this same problem as described at the top of the thread, except mine only comes into play after road-trip time in the car (hours). First happened after 5 hours. Luckily it happened just as I reached my destination, and I forgot about it. Came back on as normal when I returned to the car a few hours later.
Most recently was on a drive down to FL and it went out with a few hours left in the drive (and it was summer, in FL, in a black/black TL) so troubleshooting was top of the list. I found that disabling re-circulation fixed the issue. It takes a few minutes, but under five, and comes back on as normal. I haven't had the problem since.
Most recently was on a drive down to FL and it went out with a few hours left in the drive (and it was summer, in FL, in a black/black TL) so troubleshooting was top of the list. I found that disabling re-circulation fixed the issue. It takes a few minutes, but under five, and comes back on as normal. I haven't had the problem since.
#21
Blower motor resistor would be at fault if you couldn't change the speed. You're able to change the speed because you can hear it right? I am having the exact same issue. It's ice cold then after 20 mins it will stop cooling so much and I am getting the vapor as well with the lack of air coming out the vents. I also get the expansion valve hiss very faintly inbetween too (should not hear that constantly) . My previous 06 was too cold. I was going to do a full vacuum and recharge when I had some time but been so busy, I have a feeling we may be low. I am also going to check the cabin filter regarding lack of flow.
#22
This happened to me a few weeks ago...same situation and symptoms. In the end, a local, non-dealer chain fixed it by replacing a leaking shrader valve on the AC line and recharging the system. $91 out the door. The funny thing is the dealer also said they found leak and wanted $775 to fix it. I walked away to get a 2nd opinion but had to pay the $110 AC diagnostic fee.