Now that the sweltering summer is upon us, i've noticed a few problems with my AC.

1. At idle it blows warm (well, not cold, lets say that) air. I figure this may be normal as its hard to gear a compressor to work at idle and not explode at 9000rpm. Anyone else have this problem?

2. While it works fine while crusing, up near redline it will go back to warm air. This again may be normal, as some sports cars automatically disengage the compressor under given parameters (wot, boost, rom, etc).

I know there's a TSB for AC problems, but it says something about warm/cold cycling which I don't really expierence. Mine is always warm at idle, always cold on cruise, and always warm under heavy load.

The TSB will correct this problem..

not necessarily. It didn't on mine. My ac just blows. it blows hot air at that, and not very forcefully.

Originally posted by epitrochoid
Now that the sweltering summer is upon us, i've noticed a few problems with my AC.

1. At idle it blows warm (well, not cold, lets say that) air. I figure this may be normal as its hard to gear a compressor to work at idle and not explode at 9000rpm. Anyone else have this problem?

2. While it works fine while crusing, up near redline it will go back to warm air. This again may be normal, as some sports cars automatically disengage the compressor under given parameters (wot, boost, rom, etc).

I know there's a TSB for AC problems, but it says something about warm/cold cycling which I don't really expierence. Mine is always warm at idle, always cold on cruise, and always warm under heavy load.

I have exactly the same issue and was wondering the same thing. When I got the car, I turned on the air while cruising home and nearly froze. I thought "Cool (no pun intended), I've got a good air conditioner"...that being a necessity in central Texas. Since then I've found the performance to vary alot at lower speed/rpms.

I think I've got the "cycling" issue.. if you crank it up to full high and put your hand in front of a vent, you can feel it go from cold to cool to lukewarm, and then back. Wouldn't have noticed for another month or so if the weather wasn't so messed up here... :(

I imagine that the magnetic clutch on the compressor will disengage past a certain RPM - AC compressors don't care for 9000 RPM's.

I think the high RPM's is part of the reason the '8 has an electric power steering system. Power steering pumps blow up at 9000 RPM - I know some RX-7 guys that have killed pumps from sustained high RPM's.

Can you see the AC compressor with the hood open? If so, you could see if the clutch on it was engaged and the pump was spinning at idle when the air is warm.

Dale

i just called my dealer and set up an appointment to have them change the AC computer..we'll see

Let me know if that works for you. It didn't fix mine, that's for sure. It maybe works better in cool weather, but in the heat of summer (85+ degrees) it sucks just as much as it did before the A/C amp swap.

I was thinking about getting an RX8 this comming weekend. I live in South Florida and I am a bit scared about this A/C problem. Do they all have this problem? Is there a fix for it?
-RX8J

I took it in and they seemed confident that the AC amp would fix it. But of course they had to order it...

Yeah, they had to order mine too. I haven't told them that it didn't work yet... I need to see if anyone else has a fix above and beyond the ac amp.

My 8 was produced after the A.C problem but it still wasn't cooling that well. And i couldn't figure out why, i would get cool air never cold air, then i would get a little warm air. and the other day i turned the ac on but put it to fresh air instead of recycle. And the air got colder then it's been before. The normal is to put the recycleing side right away and it usually cooled on my other cars i had before. Well anyways like i said i put it to fresh air and the air got cold, colder then it ever has before then after it got cold i switched it to recycling mode and it got colder. and it stayed cold during all the stop and go traffic around town. And i haven't had a problem with it yet. So try that if you think your ac isn't working right. It might or might not work doesn't hurt to try. But the air is cold real cold.

I've actually tried every combination that I could think of, that one included. But thanks for the info. Maybe someone else will have that same phenomenon.

The new amp didn't fix mine either.

So what is the verdict? Do all of the 8's have this problem or is it limited to a select few of them? I am going to the dealer on Sunday, and I will be critical of this issue (thanks to this forum). If the problem is not model or design specific, I can look for one that blows cold air (on a Sunday afternoon in FL I will be able to tell quickly). If the problem IS from problematic design I dont think I can tollerate it, and I'll have to wait for a fix till I get one..... and I will get one .... oh yes :p

-RX8J

I have noticed now that I got the new amp that when I turn on my AC that the default is max curculation. This was not the case before the new amp. Any one else experiecing this?

Depending on what vents are open determines that. No matter what you had it set on (re-circ or fresh air), it changes to the "suggested" mode when you change what vents are open. I think dash is recirc, dash and floor is fresh, etc.

an informal evaluation of my "coldness" on my way home this evening suggests that RPM in the 3250 +/- 250 RPM range produced the best results for me. Ambient was (according to the dash) 94 deg. F.

bought my 8 a week ago and have put 1000 miles an a weekend trip . it was 85 to 91 outside and my air worked great. i do have a automatic if that may make a diffrence i am not sure ,but all the problems on the earlier ones seems to be fixed in mine. Great power once the car learned how i drove and the handling is like no other car i have driven. so good luck on your search

I have had the AC amp fix for the past 2 weeks now. I dont have the cycling anymore. However, I do notice it gets significantly colder at highway speeds. Before the fix it would noticible cycle from warm to cold to warm to cold at idle or at speed. Now it goes from cold to colder to cold to colder depending if Im stopped or moving fast. This with 80 degree weather!!

A/c amp change did not fix my a/c issue as well.

A/c amp change did not fix my a/c issue as well.

A/c amp change did not fix my a/c issue as well.

must have REALLY not fixed it!

yesterday me and fiance went for a cruise it was almost 90 min of driven hwy, city, traffic and back on the hwy. at almost 90 degree temp..... the a/c would do the cycle ........but has any one expirience water dropps from under the pasanger side....

Guys-My AC on max cold will get very cold for 10-12 seconds then will get warmer but still cool for 5-10 seconds then will get very cold again. This cycle will go on indefinitely and is associated with hearing engagement of AC clutch intermittently. Is this totally normal and not related to TSB? My VIN falls just after the ones in the TSB.

Thanks!

Bob

dr what about the water dripping inside

Dear d0va,

No water dripping inside. Seems to be same whether on fresh or recirc.

Thanks,

Bob

no actually water drops felt on her sandals and toe like 3 drops.....

Originally posted by d0va
yesterday me and fiance went for a cruise it was almost 90 min of driven hwy, city, traffic and back on the hwy. at almost 90 degree temp..... the a/c would do the cycle ........but has any one expirience water dropps from under the pasanger side....

It is normal for an AC to have water drip outside, under the car from the condensation on the coils... It is not normal for it to drip inside the car and those cases should be looked at.

That said, I've run my AC for hours and not noticed any water undere the car when I stop...has me wondering about it, since every other vehicle I've ever seen drips water when the AC is running.

Originally posted by PHA RX-8
I have noticed now that I got the new amp that when I turn on my AC that the default is max curculation. This was not the case before the new amp. Any one else experiecing this?

I just had my a/c module (or whatever they charged Mazda $469 for) replaced last week. Mine was a pre-order so it was within the vin numbers. Now the thing is, just before I took it in, the a/c started working great even in 90+ temps. I took it in and it still seems to blow cold, but more so when moving. And the default is now recirculate which I change to flow thru as soon as it cold. I guess it's a little better than my Miata, but not nearly to the level of my wife's Benz which is a "Climate Control set and forget."
In the final analysis, the a/c works ok and keeps the interior comfortable if not freezing. One other thing though is that I now notice that the engine cooling fans run far longer after shutdown on a hot day. I don't think this is a problem (Benz does this too), but it's a difference after the TSB fix.

mine's doing the same thing..

i took it in last week for them to order the amp, but now the AC blows comfortably cool

Originally posted by PHA RX-8
I have noticed now that I got the new amp that when I turn on my AC that the default is max curculation. This was not the case before the new amp. Any one else experiecing this?

I noticed that too one day after having my A/C amp replaced. Did you notice if you move the temp control knob one "click" from the coldest setting towards warm that the recirc automatically switched to fresh air? Mine does that.

The new amp did not fix the issue in my car either. It seemed to have helped a little, but I still get the cold-warm cycling. The warm is just not AS warm. I'm going to wait until we get a nice hot humid day here and see how it performs.....if it sucks, it is going right back to the dealership.

I saw where some people posted that their freon was a little low from the factory and had to be "topped off". I'm wondering if that might be the case with some of us who still have shitty A/C even after the amp replacement?

There is a performance test for your AC that they're supposed to check to see how yours stacks up. It involves rolling up all the glass, set to recirc, idling in the shade, blower on 3, cold set to max, and seeing what the temp is right at the two center vents. I would use that to measure how well your AC does. (I think the max temp in the target range is 46F, but I haven't looked in the shop manual in a while) I tried to capture the cycling this way, but my thermometer didn't respond nearly fast enough to the changes.

Other than emperical evidence, I had the amp replaced and when I'm at speed it seems to cool better, but idling, it's just as bad as it ever was. Oh well, it's like everyone says, comfortable but not cold. As soon as I find someplace to put on 30% ceramic tint, I think my problems will go away.

If only ceramic tint wasn't so expensive! I have a friend that owns a tint shop, and I told him that I want to have a ceramic tint. He knows I like it cool in my house and my car (my thermostat at my house is set at 65 or lower year round). He told me to let him know when, and only then would he order the box of tint. Apparently it's so expensive he doesn't want it sitting around his shop eating up his open to buy! At least the RX-8 has some ceramic tint (or something resembling it) on the moonroof. Otherwise we'd all be cooking.


Speaking of which, anyone have a pic of a car with ceramic aftermarket tint? I'm sure it's not easy to see, but anything would be nice to see. It's not that common...

My air cools to a lower temperature after the fix. I measured it at 48 degrees at the vent and now it cools to around 40.

The compressor seems to cut out when at idle . . . I had the same thing happen in my rx7. I think it is designed to do that. Part of the "fix" was to have the system default to recirculate when the tempurature control is set at max (which makes sense I guess).

my a/c will freeze your ass off. the only thing i dont like about it is when your at a red light the fan slows down. you can give it gas and it will speed up again

Originally posted by Boozehound
There is a performance test for your AC that they're supposed to check to see how yours stacks up. It involves rolling up all the glass, set to recirc, idling in the shade, blower on 3, cold set to max, and seeing what the temp is right at the two center vents. I would use that to measure how well your AC does. (I think the max temp in the target range is 46F, but I haven't looked in the shop manual in a while) I tried to capture the cycling this way, but my thermometer didn't respond nearly fast enough to the changes.

They (the Mazda dealer I took my car to) did this test and said everything was fine - but they agreed to replace the AC amp which I'm still waiting for.

Apparently their thermostat did not respond to the temperature cycling cold-warm-cold... every 2-3 seconds. So in my experience, the test your described was totally useless with the AC amp problem.

rx8cited

Guys-I live in Huntington Beach, CA where temp is always less than 80 F. Past week more tepid than cold air blows and I finally took car in today to dealer even though my VIN did not apply. After leaving car all day AC amplifier is on special order and may take a month to arrive! Glad I do not live in Las Vegas. This was my first visit to local service and gave them box of baked goods to go with their coffee-produced immediate smiling and very positive attitude on their part. Not saying we should all do this but goes a long way for good will.

Bob

Yeah, mine is great when moving at normal speeds. But at idle, when it is extremely hot outside (> 90 here in Austin), its kind of luke-warm. It always seems to be a problem when idling. Once the car moves for a bit, it seems to get much colder.

yep, thats it...my civic did the same thing, but not nearly to this extent.

The compressor cuts out at idle . . . as it did on my Rx7.

Just got mine back from having them check the warm air problem at idle. At first they said the computer said everything was fine, but then I told the service guy to get of his lazy azz and drive it . He called me back and said he ordered the AC amplifier but it is on a 1 month backorder...grrrr

So is the amplifier not fixing the warm air at idle problem?

The TSB did not fix mine either, but I would rather have that right now...the high today here in the desert is 112 degrees with 75% humidity! Not fun, but hopefully enough feedback will get to MNA and they will put some effort into a real fix.


Originally posted by snap-on
The TSB will correct this problem..

Hey! It's over 100F here in Phoenix, AZ ! Now that's hot.:cool:

Interior car temperatures can approach 170F in a car left in the sun so what we've learned to do out here is to start with the AC on fresh air with the windows down and sun roof open for 1-2 minutes. This lets the superheated interior air escape. No point in trying to cool 170F air when fresh is only 115F!

Originally posted by miniviper
the other day i turned the ac on but put it to fresh air instead of recycle. And the air got colder then it's been before. The normal is to put the recycleing side right away and it usually cooled on my other cars i had before.

I had the AC Amp changed and it did improve, but Mazda needs to continue to work a fix. This level of performance is unacceptable.

Originally posted by boarder
Yeah, mine is great when moving at normal speeds. But at idle, when it is extremely hot outside (> 90 here in Austin), its kind of luke-warm. It always seems to be a problem when idling. Once the car moves for a bit, it seems to get much colder.

This is what I'm experiencing.....which is in no way acceptable in my opinion. Any car that I have had prior to this one has never had an issue like this, so even after the new amp something is still apparently not fixed "all the way" with this. If I get stuck in traffic idling for an extended time, mine will eventually blow lukewarm humid air.


I will most likely be sending mine right back into the dealership again to see if there is anything they can do with it. I AM NOT putting up with this again all of this summer. I about freeze in my 1991 RX-7 convertible (black on black even!) with the A/C on fresh air and the blower running mid-speed. I don't think the A/C has ever even been charged or anything on that car and it has 96k on the odometer. A/C works 10 times better on that car than on the RX-8. Guess I'll be driving that car a lot more this summer if they cannot come up with a fix for this.

MNA.....you reading this??? FIX THIS PROBLEM!!

Tired of sweating in my car.......:mad:

Same problem w/my A/C. Dealer says TSB does not apply to me because my cars' build date is after 09/03. The A/C amplifier is already updated and Mazda says all is fine. I've talked to other RX-8 owners w/same issues. Not happy w/a/c and I will continue to complain

Dear Ron Rotor,

I have same issues and my build date is 11/03. I took into dealer and they ordered AC Amp-either they do not know and will not help or will. My VIN is not within MNA says is affected cars but am hoping will help but back-ordered till July. Maybe that's why your dealer is balking?

Bob

I recently took my car in because it got flooded (fuel). I got it unflooded and got it flashed up to 'M'. I also had them work on the annoyance of the running water sound. All seems fixed.

Also bitched about the A/C and they supposidly order a "thermistor". Thermistors are defined as "thermally sensitive resistors and have, according to type, a negative (NTC), or positive (PTC) resistance/temperature coefficient". They say it's on back-order, which sounds familliar to what you are all saying about the AC amp, but are they the same thing?

I'm having the exact same problem where it cycles on and off. If it always stayed on the 'on' part of the cycle I'd freeze parts of my body off even in the Houston weather. But it cycles off for far too long in my opinion.

Anyway, just thought the work they're performing on mine sounded a little different then what they're doing for you so I figured I'd mention it. Like I said, the part is on back-order for an undetermined amount of time, but I'll let you know if it made a difference when they finally do get it installed.

Regards

DAmn, with this many people having the SAME problem, MNA better do something..... My AC Amplifier is backordered until JUly. I'm going to raise complete HELL when/if the problem happens again.....grrrr

Dear former_s2k'r,

Let's not all shoot the messenger(service people) but fire many shots over the head of MNA and let them know if MNA wants to retain customers they better get their act together.

I definitely agree with you-if problem is not solved after waiting months for parts-we should all come down hard on MNA.

Bob:mad:

I live in the SE U.S. today it was 94F degrees with 97% humidity. I have an all black interior and you bet its hot when I open the door after work, however when I get in I open the sun roof, roll down the windows, turn the AC on full take off and 1/2 mile down the road and the AC was nice and cool. Im thinking about getting the sun shade it should help.

I asked the Dealership (128 Mazda) to confirm the A/C was working properly while the 8 was in for an Oil Change.

The dealer said that there was a 30 degree differential between ambient and vent temp. They claim that's acceptable.

I still think it takes too long to cool down such a small car.

NEWireless

The dealership I bought my car from claimed the same thing. They also claimed that there wasn't any reason to get my PCM calibration updated. In other words, the dealership I bought the car from has a bunch of lazy bastards working in their service center.

I now take my car to another dealership. Their service center upgraded my PCM and told me that it was actually several revisions out of date. Rather then tell me that the A/C was "within acceptable range" like the first dealership, they promptly ordered me a replacement part.

If your dealership isn't giving you the service you expect, go elsewhere.

On a side note, the Thermistor I was referring to earlier is apparently part of the A/C amplifier. Looks like I'm getting the same TSB as the rest of you after all. It doesn't look like there is a clear answer as to whether or not it really helps, but I'm certainly not going to tell them not to do it.

Had mine in today and they claimed all was within specs. However, when I got home I checked the numbers from the service invoice against the workshop manual. The high-pressure reading was in the normal range, however the low-pressure side reading was 35 psi. The acceptable range at 75 degrees ambient temperature is between 12 and 20 psi, so it really is quite far out of spec or my manual is incorrect or some mistyping on the invoice.

An admittedly quick and not-necessarily-educated trip through the troubleshooting section landed me at either improper positioning of the expansion-valve "heat-sensing tube", or faulty expansion-valve.

So I will take it up again with our service guys and see how it pans out.

Originally posted by eXentric
NEWire

On a side note, the Thermistor I was referring to earlier is apparently part of the A/C amplifier. Looks like I'm getting the same TSB as the rest of you after all.

The Thermister is a temperature sensing probe which is plugged into the A/C amplifier. It is used to measure the the temperature of the evaporator coil to prevent it from getting too cold and freezing up. If the resistence values for the thermistor are out of spec, the compressor clutch could cycle prematurely. Good luck on your fix.