Odd Air Conditioner problem: warm from left vents, cold from right vents
 

Today I noticed that the drivers side vents blow warm air while the passenger side vents blow cold air.

Any ideas what would cause this or how to troubleshoot it?

Couldbe on of blend motors/doors on the HVAC box.

Not sure how the 8's work. I worked on an Audi A4 and one side blew warm due to a temp sensor in the ducting go bad. I dont know/think the rx8's have that though.

the flap to shut off incoming air might be obstructed .. do you have it on recirc when this happens?

Yes, this happens even when recirc is turned on.

BUMP - anyone?

I had this issue, researched a bunch, talked to some people. Every suggestion was wrong. All I did was get a recharge kit from car quest and charge my system. All has been good since. Get one of the kits with the gauges and test your system to see if it is low.

How hard/easy is this to do? Is there a DIY by chance?

The directions are on the bottle, grungepup did it for me because I was working on someone else's car at the time but I have seen it done before, super simple.

Thanks, I'll give that a shot. I also tracked down the RX-8 HVAC service manual. I will let you know what happens.

Just a side note here but did you remove the air filter and inspect the vent ducting? Rodents can move into the box. Recharging should not effect left or right duct temp. Either the door mechanism is broken or there is blockage. There was a thread about solder joints breaking on the AC control. Fix was to remove and resolder. Don't know if it was for fan speed or temp knob of if it's related.

Well, I had the same exact issue and everyone said it was "venting issue". All I did was recharge my system a couple of months ago and it has worked fine since then. Hell I was even pricing the AC amplifier convinced it was that.

By the OP putting "cold" air i'll assume he means in the normal range and used a thermometer to test it. If you getting in-range "cold" air out one side it's not a low charge issue. It's a blend or obscruction issue. He should of course test his high and low pressure before asking this question.

No, I haven't removed the filter yet. I would be shocked if it were a rodent. The car spends most of its time in a decidedly rodent-free garage.

It's definitely not a temp knob issue. Left vents are warm-to-hot and the right side vents are pretty cold. If I close vents on one side or the other, it does seem to affect the temperature and pressure of the other vents.

It's almost like warm outside air is coming in the left vents and conditioned air comes out of the right ones.

One thing I have confirmed is that the temperatures of both vents rise the longer the car is in operation.

Assuming you want to fix it yourself then get a set of gauges high and low and test the pressure. When you said Cold I figured you mean 58-62 degrees out of one of the vents.

^ + 1

The problem has been solved.

I picked up a gauge and can of R-134a. Sure enough, the level was low. After recharging system I now have nice cold air coming from both vents.

For giggles, I checked the air filter and found a lovely surprise. The previous owner said that it was "just changed". Well, I'm not sure what calendar he was using because the filter hadn't been changed in ages. It was not only full of dust, but there were leaves and some sort of droppings. Fortunately, there is no evidence of recent infestation. It just grosses me out knowing that I have been driving around with that in my car for over a year. I can post a picture if you really want to see it.

Thanks again for your help.

Good to hear :)

My 2005 RX8 has an intermittant AC problem with warm air blowing out the vents...it will go a week doing that and then start blowing cool air. Took it to the dealer a couple of months ago and they indicated that there was a blockage of some kind. Tried a quick fix and it worked great for a month. But problem began recurring over last several weeks. Took it to the dealer today. They can't find any leak and have told me after running a computer check of some sort that it is a short. Need to replace the air controller for $500 plus drain the freon and refill for another $600 in labor. I post on here when I have a major issue for input and advice. I had to get a new engine at 80,000 miles about 2 1/2 years ago. I have put about 34,000 miles on the new engine without problem. Because of that problem, I have stuck close to the dealer. Any advice appreciated on my AC issue!

Left/right ac reset
 

Same issue. Reset following the button combo in this video. Strange, but it worked on my 2004.

I added some refrigerant today and it worked intermittently and blew some smoke from under the hood. Then it is working perfectly but my check engine light came on and doesn't rev up to 6 grand at times. Weird coincidence or did my car just have a meltdown? What is going on?

Confirmed, I just had the exact same problem with mine: Warm air on drivers side, cold on passengers side, and just under-performing in general. I bought some refrigerant and a gauge. Level was low, charged it up, now all's good.

Hi - Newbie here (2004 RX8) w/ stupid question on the do-it-yourself recharging on my RX AC system: any recommendation of type/brand Guages to look for & best place to purchase?
Thnx

jkhuddle54

Holy hell. My AC has been giving me fits for the past year. I charged it up and finally started getting cold air, but only out of the left side vents; both floor and dash.

I found this post and followed the button reset and my AC was icy cold the whole drive home.

Thank you for posting this video.

Most Honda and Mazda AC systems have this same issue - once the refrigerant is low one side will be warm the other fine. It is a design "feature". Why your refrigerant is low (where's the leak) is another matter...

Not sure about the reset procedure - what does this actually do?