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.

 

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.

 

Normally when mist starts out of the vents it's an indication that the evap is freezing up and not allowing air to pass over the evap.
Is this on recirculate or outside setting.

 

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.

 

My car is lukewarm cold and then blows hot air with a constant hiss regardless of level on fan. What could be the issue?

 

^ 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????

 

Does anyone know what Acura does about this and the cost? I am going to take a road trip in the middle of summer and would like my A/C to work?!

 

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.

 

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.

 

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

 

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.

 

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....

 

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!!

 

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.

 

Sounds like they are troubleshooting at your expense. If the freon was low, then it just doesn't go away, did they find the leak? My bet is the sensor was/is the culprit.

 

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!

 

Hello sorry for the bump, but regarding the clutch relay and maybe some sensors and fuses that relate - I saw a troubleshooting guide online somewhere that goes through this entire process but I forgot where I saw it. Is there a DIY thread here? Or a website I could find this tbs guide? Thanks!

 

Replaced the cabin filter (clogged really bad, very dirty, surprised) and airflow is substantially higher. Did not replace the temperature sensor, will wait for long trip next week.

 

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.

 

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.

 

I was low on freon by a small amount. Now vents are pushing 6 Celsius on both sides.

 

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.