So just today I started to notice what some others have posted about with the "surging" air conditioning. Seems like it runs very cold for a few seconds then warm then cold, etc.

Anyone find out anything about this? Mine wasn't doing this until today so just wondering if anyone has talked to a service department about it and if it is normal (or why it happens).

Sitting at idle it works fine. Stop and go traffic seems to cause it to start doing the surging.

I am thinking it is something to do with the 65% cutoff. Maybe it is misinterpreting something and keeps cycling.

It still keeps me from getting hot, but still is irritating.

I smell a recall.

I drove an automatic today. Fan works great but the A/C temp was luke warm. I have heard of occaisions where the factory, or port, correct me if Im wrong, will "overfill" the A/C system. (if overfilled A/C does not work properly i.e. we get very little or no cool air) As for the surging, I did not find it happening on the car we drove. It was an automatic with three of us in the car. A/C Luke warm.

I dove 125 miles today in 80-95 degree temps. 2 hours of that was in stop and go L.A freeway driving. The a/c worked flawlessly. My only complaint is that the the jump from fan speed 1 to 2 is too much. My Acura had an infinately variable one.

There is something up with the AC. Not just coldness, but weird blow off blow on, cold-freezin-normal air, crisp then humid suddenly.

Originally posted by RotoRooter
There is something up with the AC. Not just coldness, but weird blow off blow on, cold-freezin-normal air, crisp then humid suddenly. It sounds like the HVAC controls are cycling the A/C compressor on an "as needed" basis (not that uncommon, my 1997 Jeep Wrangler did this) but that something is causing the system to wait too long before reengaging the compressor clutch.

The way it worked on my Wrangler was that the compressor would kick in and operate until the system reached a particular pressure, then shut off. This meant that on cooler (e.g. 70°F) days you could hear the compressor cycle on and off quite frequently and on hotter days (e.g. 90°F+) it would remain on constantly.

It shounds like the controls are leaving the compressor off too long, resulting in warm air being blown out before the compressor kicks back in, resulting in the "max cold" air followed by warmer, more humid air.

Just a theory - although I know an air handling expert, I do not profess to be one. :)

Originally posted by Puppy1
I dove 125 miles today in 80-95 degree temps. 2 hours of that was in stop and go L.A freeway driving. The a/c worked flawlessly. My only complaint is that the the jump from fan speed 1 to 2 is too much. My Acura had an infinately variable one.

Yep... same here. Been driving for 3 days now in about 95 degree Texas heat. No problems with the AC for me. Blows very cold air, and is very strong. Have not noticed any problem with the AC blowing warm air at any time.

i've noticed it kinda follows the revs, in really bad stop and go traffic it warms up when i'm at idle...then gets quite frosty once i break 3k rpm. it is kinda weird but i never use a/c unless i have passengers who complain about cabin heat anyhoo =p

Originally posted by javahut


Yep... same here. Been driving for 3 days now in about 95 degree Texas heat. No problems with the AC for me. Blows very cold air, and is very strong. Have not noticed any problem with the AC blowing warm air at any time. That's what makes me wonder if it's compressor cycling as I mentioned with my Jeep Wrangler. 95°F is hot enough that the system would keep the compressor enabled all the time, but Southern California has been in the 75° - 80° range all week, which is much cooler and might cause the system to cycle the compressor on and off causing the variation in air temperature from the vents...

After 2 weeks in heavy traffic and 90 degree temp I find the AC to work well enough. It definitely surges in temp during idle more than I expect from Mazda.

My 2nd gen. RX-7 and '93 Miata never displayed the same behavior as my "8".

I'm more concerned with the poor gas mileage.

400 miles so far and I probably drive too fast.

When it occurs (which isn't all the time) it starts cycling cold, warm, cold, warm about every 5 seconds or so.

But doesn't happen all the time. Wierd. I will update more info as I have it.

I'm more concerned with the poor gas mileage. 400 miles so far and I probably drive too fast. I've tried driving a few times according to the manual, and it would have you shifting at about 3000rpm! I find this hard to do because the engine is so quiet, the engine revs up so fast, and the visual cue of shifting when the tach needle is at 8o'clock (am!) is hard to comply with.

Originally posted by RotoRooter
There is something up with the AC. Not just coldness, but weird blow off blow on, cold-freezin-normal air, crisp then humid suddenly.
Well I am in the vehicle air conditioning business and I have
this same problem with mine. Took a quick look at it yesterday.
Good news it that the system is diffenately not undersized.
There is also not an issue with the refrigerant charge level
(too much or not enough). The compressor appears to cycle
on both a low pressure switch which appears to be ok and also
a signal from a evaporator temp sensor or the engine ecu.
At times the compressor does not run long enough. I need
access to the factory A/C control wiring diagram to find the
answer. It should be an easy upgrade campain for Mazda to
fix this issue.

Rock on Zoom49. Good to hear someone in the know has taken a look. Be sure to let us know whatever you find out as diagrams become available.

Hmm Had mine a week now It has been around 94 degrees with high humidity in FL . The AC compressor seems to kick in about 20 sec after starting and really klunks. Have also noticed an air fan speed changing. Air seems to work fine but takes a while to cool the black interior after being parked in the sun. I also leave it on max cool.

ALso, according to the technical CD the AC cuts off automatically when around 60 % of the throttle is opened. THat MAY account for the air temp in stop and go.

Zoom49 said:

At times the compressor does not run long enough.

On mine the vent air cools down to 45 degrees on #2 fan setting, then the compressor cycles off and comes back when temp above 50. That is when it feels luke warm coming out. It has been over 110 degrees here. It has no problelm cooling vent temp down to 45 on ither fresh air or recirculate. It is the compressor cycling off too quickly.

For posterity, I'll post that my RX-8 was doing this when I was on the way home from work....about 85 outside, and I had to throw the fan on setting 4 just to remain comfortable. I had it blowing directly on my face, and could feel it turn on, off, on, off, etc. in cycles. I was going to call Mazda and tell them it was faulty...but it looks like it is happening to a lot of you. Let's all call our dealers so they know the issue exists.

With the horsepower fiasco, the air conditioning isses seems almost forgotten. Do you (ZOOM49) have any additional thoughts or information?

As I indicated earlier on mine the probled is not related to refrigerant level (tried adding and removing no benifit) The
ECU of other device appears to be allowing the clutch to cycle off before the proper vent temp is achieved. Also it is NOT related to the 65% throttle issue as it also happens on mine at idle and
very light throttle on highway. I have not been able to get a
wiring schematic yet for the A/C. I will be able to help when I get this. I have contacted my dealer about getting this with no response. Ibfubar has not heard of a TSB on this issue. Will post as soon as I find out.

As I mentioned earlier, I suspect there are high and low pressure switches in the A/C system that trigger the compressor to turn on and off, cycling the compressor. This is normal for many HVAC systems, the question is why the low pressure switch is allowing things to get to the point where minimally conditioned outside air is felt. Perhaps it's a bug in the ECU software or an improper low pressure level was selected.

Regardless, until someone here gets to read a service manual we won't know for sure...

I think there may be a rumor of a new TSB, can we get anyone to verify?

I read a lot on this board that many are unhappy with the Air Condition performance. I live in Phoenix and the AC is about on par with other vehicles I have been in. The black interior sucks up alot of heat it and would have been nice to see a light grey/silver interior option. It is much beter than riding in a SUV they don't cool down till Oct.

I'm tinting next week to offset my black interior's Sun grabbing magnet. That should help dramatically.

Yea, I'm not very satisfied with the AC, I think because the cabin gets so hot from a transmission that the AC has to work harder. But AC is not a big concern for me cuz it just slows down the car.

Mine is just like lefuton stated. It only coold great when I bring the engine revs up off idle. I have not had the amplifer replaced yet as it is in that range, so hope that fixes it. Didn't check the pully ratio as Mazda could have the compresser turning slower than most cars or the RX7 since this engine goes to 9000 rpm.

the climate control we get here in europe is great, very strong
one of the best i've seen in a car

I live in the Southeast U.S 90 degree plus with high humidity and my Air Conditioner in my 8 is one of the best Ive had compared to a BMW, some Chryslers and GM vehicles that I have owned in the past. Rarely do I turn it above level 2 and if I do it is only for a short amount of time. Sorry to hear that your having these issues there is a TSB that addresses this specific issue as well many have left numerous posts discussing this same subject with tips tricks etc.

here is the TSB from 4-22-04. I had it done to my car a few weeks ago. AC is a little better, but not great.

http://www.finishlineperformance.com/rx8/docs/07-002-04.html

I cant wait until Winter starts then everyone can start griping about the heaters. :-)

Air Conditioner works great for me, noticed hints of what you are talking about, but Ive never seen a perfect air conditioning system in any car foreign or domestic and what is acceptable to me may not be acceptable to you, probably something you should have checked out before you bought the car :-).

Overall very happy with the A/C system in the 8 wish they would have given us the automatic climate control systems in the U.S. lucky Europeans you get this and the puddle lights as well.

I know this thread is over a month old, but I had to bump it.

I got my AC amplifier replaced (TSB says this is the problem) a week ago and haven't really needed to use AC until today...

it is still doing it -- WARM --> COLD --> WARM

Anyone else had their amp replaced that is getting the same old problem?

The dealer told me to come in for another replacement on Monday... I guess we'll see if it works the second time around.

Mine got the TSB, but it's still doing something... It doesn't cycle the same way, but it's doing something...

Before there would be an audible click, and a slight surge in the engine when it happened.

Now there's no sound, no surge, but it's still goes back and forth between cool and humid... it never gets really cold. I'll have to take it back in some day.

---A

I got mine done (AC amplifier) a month ago and I still notice it, its much worst now cuz the warm air is even more humid and I get a jump in the revs everytime the AC fan turns on and off. Someitmes it feels like my car is going to stall hehehe.

I haven't had any noticeable problems with the cycling. No unusual problems with my AC. Purchased in March '04. Vin 401....26***.

I park in a structure at work. It's been in the mid to high 80's in Los Angeles. If I drive out for lunch, the AC works great at fan speed 2, but not quite cool enough at 1. After sitting in the sun during lunch, with the moonroof tilted to vent, I need to blast the AC at max, but never really overcome the heat radiating from the dash before getting back to the office -- usually 10 minutes away or less.

I have winning blue which I'm sure sucks heat pretty well, but the above doesn't seem unusual.

I had my AC amp replaced last week. I drove home and it seemed to cycle the same as before. I used the AC again yesterday and it did not cycle and cooled adequately, but not great, and it was only 74 deg. outside. I will need to use it more to see if the problem is fixed. The AC in my VW and Honda are only OK too, so maybe it is too much to expect the interior to get really cool in a modern car.

All the other issues with the car have been taken care of. Oil usage is low, a quart every 3k and mileage is still around 19. It rolled over 11k miles and I love the car. If I don't have the flooding issue this winter, I will keep it for a long time. If it still floods, it will be gone and I will be at the Honda dealer.

This from a thread I started on this topic:
Measurements made with Fan on 2, Recirculate, and Max Cool.

I bought an A/C thermometer; the kind you stuff into the vent, and I'm keeping track of the air temp.

The last couple of days here have been in the low 90s so its a good time to check it. I'm making measurements with the engine cover on and off as my theory is that the engine cover traps heat. I am making measurements in both recirculate and fresh air mode, but so far there seems to be little variance in temp.

With the engine cover on:
Idling in traffic = 50 degrees
Highway at 80 = 40-42 degrees
Feels like less CFM (cubic feet / min) of air from the vents

With the engine cover off:
Idling in traffic = 46-47 degrees
Highway at 80 = 40 degrees
Feels like more CFM from the air vents

In my garage, the compressor duty cycle is:
On for 10 seconds
Off for 5 seconds

I don't have the AC fix yet. One thing I noticed in the garage was the duty cycle of the compressor and its relationship to the main cooling fan.

I can hear 2 fans in the front of the car. One is significantly louder and beefier sounding so I figure it is the main cooling fan.

When the compressor engages, the second smaller fan comes on. But here is the weird part. If the other fan comes on while the compressor is on, it shuts off when the compressor does. I'm not sure why; just seems they should be unrelated.

I too find it odd that the engine cover could have any effect, but it seems to. I don't have a meter to measure CFM so my statistics are subjective there.

My neighbor has a very old RX7; 90-92 model. He and I were talking about it and he said that on fresh Freon it would literally freeze your face. He said it was about 34 degrees. I attribute that to the pre-ban freon most likely. The kinder-gentler refrigerant (Freon is a trademark of DuPont) we use today just doesn't get as cold.

I'm going to put this into the punchlist I am compiling for the Dealer. Data never hurts.

Chrisbert

Could this have to do with MNAO's wonderful decision to pull/disable the climate control that the rest of the world gets? There was a post in this thread from someone in Europe saying that their climate control works wonderfully.

Perhaps the climate control was improperly disabled?

Could this have to do with MNAO's wonderful decision to pull/disable the climate control that the rest of the world gets? There was a post in this thread from someone in Europe saying that their climate control works wonderfully.

I think this is the answer. It was designed for climate control and when they changed it became unbalanced. The new amplifier only makes the warm cycle longer and no cooler cycle there for less cooling over all.

.....The new amplifier only makes the warm cycle longer and no cooler cycle there for less cooling over all.

That has not been my experience with my new amplifier. It's much better than the old one.

I don't feel the air temperature cycling like it did with the old amplifier. I've found the A/C performance with the new amplifier to be acceptable even on sunny, hot, humid 90 degree days. In stop-and-go traffic I sometimes have to keep the air control in the recirculate position to keep the air from getting too warm.

rx8cited

My car is in the shop today for drifts to the left if steering wheel is kept at dead center and the volume on driver side is louder then the sound that comes from the pass side. I was told by dealership that this happens becauxe of the slope in the road and such. What BS they told me, I tried it on the opposite side of the road and it was even worst. So I took it in today and they put me into a Chevy Venture. OHHH, OOHHH, O the AC is so cold. Dont even need to go pass fan speed 2 or my hands would freeze on the wheel, and its 101* F today in Fresno CA.

...but so far there seems to be little variance in temp.

With the engine cover on:
Idling in traffic = 50 degrees
Highway at 80 = 40-42 degrees
Feels like less CFM (cubic feet / min) of air from the vents

With the engine cover off:
Idling in traffic = 46-47 degrees
Highway at 80 = 40 degrees
Feels like more CFM from the air vents


Chrisbert

Have you noticed the low pressure tubing going right under the engine cover to the cabin heat exchanger?

In my theory this tubing gets warm or even hot within seconds after the compressor stops (clutch engages) and this might cause the increase (or cycling) in air temps. If the engine cover is in place it makes the space around the tubing even more filled with hot materials.
I checked my GT, and found the low pressure tubing insulated all the way in the engine compartment! That seems to be the proper way to me.. I'm getting some insulation and we will see.

Yes, I noticed that. It is what led me to investigate the engine cover theory. But, I think the refrigerant in that portion of the tubing has already done its job. I think the expansion valve is behind the firewall and the heat exchange takes place before we see the tubing headed back to the compressor.

Try the insulation though, and let us know.
Chrisbert

That has not been my experience with my new amplifier. It's much better than the old one.

I don't feel the air temperature cycling like it did with the old amplifier. I've found the A/C performance with the new amplifier to be acceptable even on sunny, hot, humid 90 degree days. In stop-and-go traffic I sometimes have to keep the air control in the recirculate position to keep the air from getting too warm.

rx8cited

Well my car made a liar out of me today :confused: .

I've had the new A/C amplifier for almost a month.

Today it was 86 degrees, quite humid, I had just started driving and was going about 45 mph, A/C on, fan on speed 4, air in recirculate mode, upper level only, and I felt the vent air temperature cycling for the first time since I've had the new amplifier.

Cooling was still acceptable and I did end up having to turn the fan down a few minutes after I noticed the temperature cycling because I was getting cold. I could not feel the temperature cycling after I turned the fan down.

rx8cited

I live in Las Vegas and although the TCB has improved the hot-cold-hot cycling it hasn't eliminated it. It is noticably better than before, but the air is not as cold as on my Protege.

Well, had my amplifier replaced about a month or two ago. It still cycled but not as noticably and cooling was sufficient if moving. I did notice that the system was cooler when I ran the fan at 3 rather then 4. Doesn't make a whole lot of sense, but whatever.

Last night when I got into the car to drive home, I kicked on the A/C and something strange happened. I heard a very audbile (but not terribly loud) hissing sound and the air did not get cold. I fiddled with it for several minutes. I turned the A/C button on and off and turned the fan on and off. Every time I engaged or disengaged the A/C the hissing sound came and went. So I turned the thing off and drove home with the windows down in Houston TX :(

This morning I tried again. No hissing sound today, but still no cooling either. It feels like the compressor is engaging because the engine hesitates like it does when the compressor first engages, but no cooling whatsoever. I can get heat out of it by adjusting the temperature dial just fine, but setting it on its coolest setting is just like recirculating with the A/C disengaged.

I have an appointment for tomorrow morning to drop it off. I'll post the results.

eXe

I've been running the AC a bit more since the new amp. It still cycles about the same and does not get the car cool if the sun is out and it's above 75deg. I notice the new amp automatically defaults to recirc. when the AC is turned on. If I put it to fresh air, the car gets warm even on fan speed 3. I'm going to complain to the dealer and see if there are any other remedies out there.

Sounds to me as if you have lost all your refridgerant. Keep us up to date please.

I've noticed something with our AC system. When idling or semi low speed, it's basically not working at all. However, once you get into cruise speed, it gets extremely cold. Gets really annoying when you're stuck in stop and go traffic. I wonder if the AC fix would actually fix it.

I've noticed something with our AC system. When idling or semi low speed, it's basically not working at all. However, once you get into cruise speed, it gets extremely cold. Gets really annoying when you're stuck in stop and go traffic. I wonder if the AC fix would actually fix it.

I have the fix. Nope, still gets warm in stop-n-go! But I usually hit recirculate when I get stuck in stop-n-go traffic and I feel the air getting warmer and that helps.

rx8cited

>I've noticed something with our AC system. When idling or semi low speed, it's basically not working at all. However, once you get into cruise speed, it gets extremely cold. Gets really annoying when you're stuck in stop and go traffic. I wonder if the AC fix would actually fix it.


Yup, thats the problem I have with the AC system. Its darn hot here in Austin (TX), and the idle AC takes a long time to cool. Especially if you started your car and promptly have to wait at a stoplight. Once your going, it kicks in.

Sounds to me as if you have lost all your refridgerant. Keep us up to date please.

Yes, that appears to be the case.

Last week, I was traveling down the freeway and there was a large sheet of something that looked like fiberglass in the road. It was probably 3/4" thick about 3 feet wide and 4 feet tall. When the car in front of me drove over it, the wind caught it and it flipped straight up into the air. I hit it dead on at about 85 MPH and it shattered.

Chunks of debris dented and scratched my hood. The wind carried the chunks down the side of my car scraping along the way as well. I was pissed, but there wasn't anything I could do. A co-worker suggested I contact my insurance, but I didn't want to hit my premiums and figured I'd just save up until I could get the body work done.

Well, apparently a chunk got through my radiator and put a dent or small hole in my condenser. Over the course of the last week, the Houston heat and the pressure in the condenser caused that dent or hole to widen. Finally, the other day when I heard hissing as I turned the compressor on and off I believe I was compressing all of my coolant out into the atmosphere. That explains why I heard no sound the next day when I tried again.

Mazda quoted me $680 USD to do the repair (condenser and labor). Now I had no choice but to contact my insurance company. I told the lady the whole ordeal and she asked me “So, the debris was airborne when is struck your vehicle?” I replied “yes”. She proceeded to tell me that since the debris was airborne there was nothing I could do and it would be filed under my comprehensive rather then collision. This means my premiums should change very little (if at all) and I have a $500 deductible. So, the A/C is getting fixed today and the body work will be addressed next week.

The road hazard was out of my control, so I suppose I consider myself lucky. This doesn’t appear to be a defect in the vehicle.

Regards,

eXe