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Mazda RX-8 Problems and Solutions

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Comments

  • pathstar1pathstar1 Member Posts: 1,015
    The recalls are required. Any dealer should do them without charge, if not they could get into trouble with Mazda NA. There are several recalls on earlier models, but the 2005s have most of them addressed already (fixed at the factory before shipment from Japan). The early 2005s still have a few to address. As I said, they should have been done already. The dealers were told to do them on all cars on the lot.
  • jakebebberjakebebber Member Posts: 8
    I have a 2004 RX-8 GT with the Bose 6 CD system. For some reason, most (if not all) CD's that I have which are burned will not play. I receive a "Check CD" error message. I have either Windows Media Player or iTunes to use to burn CD's. Can anyone tell me what the problem might be?

    Thanks!

    Jake in Orlando
  • matgarciamatgarcia Member Posts: 1
    hey got a question, last night i was driving and as i was trying to go fast the enginge just revved, then finnaly caught up. after a while of this problem it starts becoming worse and worse to where when i really need to go over 30 its not doing it. turns out teh clutch burnt up on me..anyone else have this problem?
    Mat
  • secondcitysecondcity Member Posts: 28
    I have a 2005 RX8 with approx. 10,500 miles. Recently-when our weather dropped below 20 degrees, my coolant light would go on for about two minutes and then shut off as car warmed up. I took it directly to the dealer and they reported all coolant levels were normal. Our weather has dropped again into the low teens and single digits recently, and my coolant light (Which looks like a mini White House, but in red!)started going on for about two minutes and turning off as car began to warm.

    IS there an explanation for this. I figured PATHSTAR may have experienced similar issues because of the cold winters he has experienced.

    Any advice or tips would be appreciated. I do not want to cause any engine damage. At least I have it on record with Mazda that this light issue has appeared. Other than that, car runs like a dream. Blizzak Winter tires make driving through snow easy.
  • tiltmode43tiltmode43 Member Posts: 3
    Although I am not an RX8 owner, I have read in many forums and know about many of the issues. What you are experiencing isn't uncommon and I believe its actually due to the coolant becoming so cold it shrunk in mass thus lowering it below the sensor level. The reason the light shuts off is due to the engine warming up consequently warming the fluids expanding them.
    On a side note: Ah, I don't know what to do! Stuck in choice between the Acura RSX-S and the RX-8!
  • moadhmoadh Member Posts: 15
    I own a 2004 Mazda RX8 which has around 20,000km on it. I imported it from the states to Dubai, U.A.E (btw its the only rx8 in the city, which makes it simply the center of attention) but the issue im having is ordering spare parts. we only have one mazda dealership here and they are in all honesty INEFFICIENT. everytime i want to order a part (even if its a brake pad), i have to wait a month till they order it from japan! in any case, i was wondering how many spark plugs the rx8 uses so that i can order them in advance?
  • pathstar1pathstar1 Member Posts: 1,015
    Four plugs total, two of each type, that is, two leading plugs and two trailing plugs. You have a choise of three temp. ranges. I recommend in Dubai you use the standard heat range (should be in the owners manual).
  • moadhmoadh Member Posts: 15
    For all owner-maintenance related issues, i use a 5,000KM interval. The mazda dealership recommended this since the weather here (in the summer) is extremely hot! But thanks for your help :)
  • cynteccyntec Member Posts: 2
    Hi, this is the first time I've ever used a forum, but my RX-8 is driving me crazy and I need to find out if anyone else has this problem or knows what to do. I've had my car for a year and a half and after the first half a year it started giving me problems. The first time it happened I was driving when I heard a CLANK. The car started to lose power and then stalled and wouldn't start up for a while. When it did start up it vibrated horribly. Since then I've only stalled once but The car is forever losing power so that it hardly moves. Even on the highway I have to keep pressing the gas more and more or else it looses power. It happens randomly and I can't figure out why. I've taken it to five different dealerships and they all tell me that they can't find anything wrong with it so they can't do anything for me. I did not pay the amout of money I paid for this car to get a LEMON! Can anybody help?
  • moadhmoadh Member Posts: 15
    Did you try checking either the battery or the fuel pump? it could be one of the either, very strange tho! never heard this complaint before......
  • cynteccyntec Member Posts: 2
    I took it into the dealer FIVE TIMES! They couldn't find anything wrong!
  • moadhmoadh Member Posts: 15
    Well if your car is under warranty, then they should replace it for you if they cant seem to find the defect!!
  • gjfunkgjfunk Member Posts: 1
    I have a 2004 RX-8. After having it for about a year, i have continuously had trouble with it idliing rough and loosing power. I was on the interstate going about 75 and all of the sudden couldn't accelerate and started loosing RPM's. I happened to be in the inside lane and had to go into the median. It finally started back up. It would die at red lights and times. The dealership couldn't find what was wrong with it. The engine light would come on. They did recalls on it. They ordered new computer system for it. They put a new engine in it, new alternator, new battery and after having it now for over 7 straight weeks, have ordered another new computer system for it. They can't seem to get it fixed. I have had my RX-8 in the shop off and on since September of 2005 also. I think this car is definitely a lemon!!! I think it has been about 50 days since I have had my car to drive but I am still paying a car note and insurance on this car....isn't something wrong with this picture???? They have given me something to drive BUT...it is not in the same price range. :mad:image
  • qbrozenqbrozen Member Posts: 32,889
    what state are you in? look into your lemon law. I think i read that most states put the limit at 30 days in the shop for the car to be declared a lemon.

    '11 GMC Sierra 1500; '08 Charger R/T Daytona; '67 Coronet R/T; '13 Fiat 500c; '20 S90 T6; '22 MB Sprinter 2500 4x4 diesel; '97 Suzuki R Wagon; '96 Opel Astra; '08 Maser QP; '11 Mini Cooper S

  • secondcitysecondcity Member Posts: 28
    Is your car the automatic or manual transmission?
    Past messages on this site have discussed issues with the automatic "suffering" from low revs and carbon build up. I am probably not making a lot of sense about this, but if you review earlier posts from late '04 and early '05, this topic is discussed in more detail. I feel terrible that you are experiencing this problem. I hope researching the earlier posts helps you out a bit because I recall several people with '04 automatic transmissions having this problem. Good luck.
  • articistarticist Member Posts: 9
    Here we go, I am finally posting. First of all, I would like to thank all of you for sharing experience of owning RX-8 and some of you(pathstar, in particular) for very useful info.

    I bought my 2004 red MT RX-8 last summer as used. It performs just as everybody raved about it. I had no problem and it seems that it had all the updates.

    Just today, though, I finally ran into the quirkiness of RX-8. I let the car sit for about 5 weeks and the battery is dead. It seems from old posts that batteries in RX-8's are a little weak. In fact, when I first had a test drive at a Mazda dealership, the car wouldn't start! When I decided to purchase the car I had the dealer replace the battery with a new one. Living near and working in Manhattan, I use public transportation to go to work. Thus I don't drive the car everyday. Usually, weekend joy ride is when I take this red hottie out of the garage. It is a few weeks ago when we had a snow storm I hadn't started my RX-8 since.

    Well, can someone tell me if 5 weeks are long enough a time for the battery to drain? Should I be worried about any electrical problem? I was a little worried since last time I drove the car I had to help my girlfriend with her car by jumping it with mine. It was dark and yes, I made a stupid mistake to connect the cable in reverse polarity. Funny thing is that it cured the problem of my girlfriend's car, which was having not weak battery problem but (in my opinion) some dirty relay (or something like that). My RX-8 didn't seem to be affected and I was able to stop and start the car later that night. Anyway, jumping my car (with my girlfriend's when it is bright tomorrow) will probably answer this question, but any insight from those of you who are knowledgeable would be helpful for future reference.

    Thanks and Happy New Year/RX-8ing, everyone!
  • pathstar1pathstar1 Member Posts: 1,015
    You may have fried the charging system by reverse polarizing it. If you have a voltmeter a quick check can confirm if it is ok or not. The battery is now dead.

    1. First I'd charge it with a charger. Disconnect it from the car when charging to make sure the charger doesn't harm the electronics - just the -ve terminal is fine - we always disconnect the -ve terminal first because we know we are human and can make mistakes. If you manage to touch a chassis part with the wrench on the -ve terminal nothing will happen. If you disconnected the +ve terminal first and touched a chassis part bad things would happen! Once the -ve terminal is disconnected you could ground the +ve terminal to the chassis and nothing would happen.

    2. Once charged, you can start the car. Before starting, connect the voltmeter to the battery - right at the posts if possible. Have someone help you (let them start the car). When cranking, the voltage shouldn't go below 11V. If it goes to 10 or less you have a dead cell and need a new battery (the batteries Mazda uses are known to be of poor quality, and even a "new" one can fail quickly).

    3. The car starts and runs. You should see at least 13.5V on the battery during fast idle. If you see only 11.5 to 12.5 Volts the charging system is fried. The regulator usually goes from reverse polarizing. It's in the alternator, so a new alternator would be in order.

    Your description of the battery going dead in a month is indicating you got one of the poor quality batteries from Mazda. They should replace it. You may or may not be able to get an alternator under warrenty. I wouldn't give you one, but I would give you a good discount on one because it could be argued that the poor battery was partially responsible for the damage (and I like to please customers - but I'm not a car dealer so take that for what it's worth). ;)

    Good luck!
  • articistarticist Member Posts: 9
    Thanks for the info, pathstar.

    Let me tell you what happened. I jumped my car the next day with a spare battery lying around in the garage and she started with no problem. After driving around for an hour, it seems that the battery is recharged. Yesterday, I purchased a DMM and checked the voltage in all three situations you mentioned. The readings were all okay. It was 12.5 sitting still, 11.5 cranking and 14.4 fast-idling. The chargins system and the battery all seem okay though the battery went out quite fast (~ 1 month). Reading my previous post, I realized that it sounds confusing and figured maybe you thought I jumped my car while reverse-polarizing. My RX-8 was "giving" jump and she was running at the time. It seems to me the danger of frying the system by reverse-polarizing is lower when your car is on the giving end, is that right? Anyway, I am just relieved that there appears to be no damage to my car.

    I guess that 5 weeks are too long a time to go without recharging for this puny Mazda batteries. I don't think I can ask the dealer for another replacement now that it seems there is no dead cell. Besides, they will put in the same kind again anyway. I panicked a little bit this time since from my previous experience with two Toyota Supras ('85 and '92 models) I could leave the cars in the open lot for about two months (in winter) being out of the country and still come back to start them with no problem!

    I might have to leave RX-8 for a month or two again and I know that in an (way) earlier post you talked about how to keep the car without running for a while but here are my questions:
    Are there any other brands of batteries that are stronger and fit RX-8? I saw on the internet an automatic charging system that can be installed in the car permanently. Is it any good?
  • lhesslhess Member Posts: 379
    that sat on the lot a LOOOOONG time before I bought it in March 2005. The battery was dead at the time of my test drive, they charged it when I decided to buy and I don't have any problems with it if I drive it every few days, but if it sits very long it takes a long crank to get it going. My guess is, mine would be dead long before 5 weeks were up. I haven't even taken care of the recalls yet (shame on me, I know) but when I do, I'm going to ask about a stronger battery for it. If they say no or want to charge me for it (no pun intended), I'll pass - I can get by with the one I have.
  • pathstar1pathstar1 Member Posts: 1,015
    If a lead acid battery is allowed to discharge it shortens its' life. This is because when discharged, the electrolyte has less acid and more water in it. This allows the lead plates to "sulphate" (instead of sulphite). The sulphate insulates the plates. It will fall off under vibration, but it also (poorly) conducts electricity, and if it builds up at the bottom of the cell cavity it will bleed off the battery charge by contacting the plates. This is why a battery that has lost charge and was left sitting will never hold a charge if left sitting for a month again. It is possible to fix this - I've done it with a motorcycle battery. You have to charge it up fully, drain the electrolyte while shaking it (to keep the sediment suspended in the electrolyte) and filter the sediment out of the electrolyte. You then pour the electrolyte back in the battery. I was young and cheap when I did it. I wouldn't recommend anyone try it as it is messy and potentially dangerous. And you end up with lots of toxic residue (lead sulphate and sulphuric acid soaked filter medium).

    If you want to be sure you take good care of your battery (the easy way), get a "battery tender". It's a low power well regulated battery charger. Keeps the battery from discharging. You can install it in the engine compartment and just leave the plug slightly hanging out of an opening in the grill. You just plug an extention cord into it. Those of us who live in the "great white north" know all about plugging in our vehicles. ;)

    There are lots of good quality batteries available. Usually, the ones with really good long life warrenties are well built. If they weren't, the company would loose a fortune replacing them all the time. The RX-8 battery is an unusual size, but I'm told a standard size (taller) will fit - though you may not be able to use the battery cover with a larger one. Mazda offer a larger "stock" size, but the dealer isn't the best place to buy a battery.
  • eclipse4eclipse4 Member Posts: 2
    I don't have an RX-8, but my friend and I both expierenced this problem at the same exact time. My car has a temperature guage and his just has a warning light. I would notice then when my car started up, if I just let it sit, the temperature would go up real fast. I'd usually have the heater going (uses coolant as well). Same thing would happen when I'd sit at stop lights for several minutes. When I'd start moving it'd be fine. What I found out was that I was very low on coolant, but when I was moving there was so much cold air coming into the engine it didn't matter. It ended up being a small leak in one of the hoses that connects my engine to the radiator. Those coolant warning lights don't measure mass of coolant -- they're generally just warning lights for when the temperature of the engine gets too hot.

    I hear the RX-8's are sorta cumbersome to work on under the hood, but it shouldn't be too hard to find the radiator, pop the cap, and put in some coolant. If you have to put in a lot, you got some problems. You can also check the overflow tank too. Do all this when the car is cold and hasn't been driven for several hours at least.
  • trispectrispec Member Posts: 305
    Looks like a bungi cord caught my left front wheel rim and got slung up on top of the fender. I was going 70mph in the left lane and heard a loud bang. It put quarter sized dent and two scratches that fit the shape of the metal spring end of a bungi cord. The dent is right on top next to the nice crease on the fender.

    I bought the dent kit, "Ding King" product. Looks pretty logical how it works. Has anyone used this product?
  • moadhmoadh Member Posts: 15
    Just wanted to know if anybody else is facing this problem, i know that the rx8 is known for very high fuel consumption (smth like 10mpg) but with my rx8 its just crazy. on a full tank, i would consider it an achievment if i can get upto 300KM of mileage! is that normal or otherwise? if anyone has any tips on lowering the consumption please let me know, fuel prices are just getting higher and higher (even though i live in UAE, where we have 1001 oil fields!)
  • trispectrispec Member Posts: 305
    My RX-8 AT get's 14-16mpg in Boston's heavy traffic. If I drove with the RPM above 4000 constantly, like the RX-8 wants to drive, she would probably only give 10-11mpg. She gets 18mpg in country rural driving. She gets 22-23mpg on pure highway, but I averaged 84mph on my last five state trip up and down the eastern USA.

    Keeping RPMs between 2500-3800 gives me the results above. But I do let her run free when I can. With the RX-AT it's really easy to use the paddle shifters under full power to hold back on the RPMs. Of course I'm definitely giving up the higher end house power boost. But one can't really drive with the higher RPMs in Boston traffic.
  • moadhmoadh Member Posts: 15
    Hehehe if you thought Boston traffic was bad, you gotta see Dubai's.. My brother lived in boston for quite a few years, i can recall all the gridlocks; especially in that long-[non-permissible content removed] tunnell, forgot what it was called! hehehe but in some spots, in Dubai, traffic gets even worse than that. PLUS, i drive a MT! oh well, i guess its the price we hafta pay for having such a sweet ride ;)
  • ukjimukjim Member Posts: 63
    I havent seen too many postings about this issue so I am wondering if it is somehow specific to my car, an'04 MT with 12K miles on it.
    On a 60F foggy LA evening I am stuck in slow moving traffic and within about 15 minutes the air coming out of the vents is about 75+F (Mode is fresh, not recirc), this coupled with the transmission tunnel temp gets the cabin to uncomfortable temps really quickly. I have a choice, open window and be deafened by traffic noise or put A/C on and get even worse mileage and power loss. I cant wait for summer! Has anyone else experienced heating of the fresh air vent air?
    Thanks
  • trispectrispec Member Posts: 305
    I test drove an early Group 1 2005 RX-8 AT which appeared to have the same issue. I was worried enough about it to jump into the back seat to see what the temps were like for the passengers. It was uncomfortable if the car was sitting and idling. I had read complaints about the poor AC of 2004 and early 2005 RX-8s. I however bought a Group 2 2005, which cools like a champ. In fact I find the AC in my Group2 RX-8 works so well, that I'm turning down the cooling more often than not

    I think the PCMs in the latest flash updates keeps the AC on when it's idling constantly.
  • ukjimukjim Member Posts: 63
    Thanks for the feedback trispec, I guess my concern is that with the ambient air being only 60F, or less, I shouldn't need to use A/C.
    My new job requires commuting in traffic where I will sit for upto an hour in stop and go traffic. I can live with the MT, but not roasting at the same time. I am aware of the weak A/C but didn't figure on the need to use it in such low ambient temperatures. That the outside air is being heated in excess of 15F in such a short distance, suggests it is being pulled from very close to the engine, not a happy proposition in LA in the summer!
  • moadhmoadh Member Posts: 15
    Surprisingly, i have a 2004 MT RX-8 (and i live on the hottest spot on earth, where tempratures go as high as 48C) but the AC in my car is absolutely outstanding.. in fact, even under the sun i get chilly inside!
  • trispectrispec Member Posts: 305
    I've heard about the tunnel heat factor, but haven't experienced anything but some minor warmth to the touch. There was something about the MT tranny directly heating up stick shift area simply due to the direct connection to the engine area. The heating would crack a seal or something. Pathstar sent around the service recall PDF I believe, at least I remember seeing pictures of the stick shift in the service recall PDF point to the problem. PathStar should be the one chiming in here I think.

    As for my Group 2 2005 RX-8 AT sports package, I can't complain as there no heat problem at all after 7500 miles. We just did a 2000 trip down south and I can tell you I has turning the heat up via AC on the 60F days. Of course, there's not much idling in traffic in the mountains of western NC.
  • ukjimukjim Member Posts: 63
    I hate to be redundant on this but my whole point is that with low ambient air temperatures <60F (<15C), the fresh air is coming into the car at >75F (>24C). I know I will need A/C in the summer but why do I need it in the winter? I am sitting idling in stop & go traffic for an hour, is it normal to have the outside air heated even with the fan on the highest setting? Do I have an obstruction, is the ducting incorrectly connected?
    When moving at speed it is not an issue.
    Thanks
  • trispectrispec Member Posts: 305
    Ugh, I can be very thick at times sorry. I run the AC constantly even in the winter. I like the dry air and need AC to keep windows defogged. I don't think I've ever turned off the AC since I brought my RX-8 home. I'll do a bit of testing with AC off, but I know, because humidity is general constantly a factor here on the east coast, AC might as well be hard wired in the "On" position.
  • ukjimukjim Member Posts: 63
    Thanks trispec, I appreciate any help on this, given that the A/C is weak in my car (it has been in for service but to no avail)I cant imagine what summer is going be like.
  • trispectrispec Member Posts: 305
    Well I turned off the AC. External temp was 33F. Air coming into the car however was roughly 50F with the temp dialed to max cool. If the temp dial is moved to the middle of the cool range, four clicks roughly, the air coming into the car is warm.

    Wondering if it's built this way so that the AC evaporator will constantly have hot air to defrosting it. Years ago I drove a VW Sirroco that would blow a fog during summer. The VW dealer said that there was always hot air passing through the AC evaporator in order to prevent freeze ups. They said the fog was a sign the design was working to melt ice build up in the system.

    Sorry about the story. Middle age man disease.
  • ukjimukjim Member Posts: 63
    trispec.
    That's OK, I suffer from the same disease! I think I have found the problem but would appreciate someone elses experience, especially if they are familiar with the fresh air ducting. With an hour or so to waste I decided to play with all the permutations and combinations of temp and mode.
    With temp knob at full cold, if the mode is face & feet, or face only, the air is warm, if I select feet only or feet and screen, the air is cold. So, my thought is that if the temp knob isn't completely turning off the flow of coolant to the heater core, and in the first two modes air is directed over the heater core, the air would be warm. It doesn't explain however why when in the feet & feet/screen mode I can still heat the air. Does any of this make sense? I really dont want the dealer pulling the dash apart to research this because I will just end up with a bunch of squeeks afterwards. Thanks
  • ukjimukjim Member Posts: 63
    I just reread your posting and should have addressed this in my first reply, it appears that you have a similar experience; with full cold selected the ambient air was heated anyway, by about 17 F. Compared to 33 deg, 50deg is warm! Do you remember what the mode setting was?
  • modockmodock Member Posts: 55
    Just a thought. I don't have a 8 but have a 3 and experience the same thing(warm air set on cold not the warm on top cold on bottom) I think it is because there is not enough insulation between the ducts and the engine. This could also explain why you get warm air through the top vents and cold at the bottom. The vents at the bottom do not (my guess) get close enough to the engine to warm the air but the top ones do. Did you try it with the fan on high. If my guess is correct the air on high will be cooler than the air on low since it spends less time in the ducts. This may not be immediate so give it a few minutes.

    I find that it is much more efficient to crack a window when it is warm in the car and cool outside than it is to turn the vent on cold. I would need to turn the AC on to get the temp through the vent as cool as the outside air.

    Let me know if my assessment meets your experience.

    Modock
  • trispectrispec Member Posts: 305
    For the testing I described above I used the "Face/Feet" mode.

    This time of year I almost always have the "Defrost/Feet" mode selected so that I can control the fog levels on the windows and warm my feet. For this reason, I never really noticed the air temps that you were describing.

    Theory: I've got to think the AC evaporator and the preheated external air are tied together as a unit much like a modern defrosting Refrigerator. I also think that non-AC routed air and dry cool air are linked. The evidence I have for the AC/preheated air linkage goes like this.

    1) The AC evaporator collects humidity from the air at temps above 32F. I normally observe a blast of humid air that would fog my windows on starting up in the mornings. The AC would clear the screen shortly, but it was a pain to wait until I could see again.

    2) Since doing your test of leaving the AC off all the time, little to no humid air is getting trapped in the AC evaporator. The last few mornings, there has been no window fogging even though it's been raining.

    On the later link of non-AC routed air and the non-preheated air the evidence comes from this.

    1) When a mode setting contains "Feet", the air blowing from the feet is cooler than "Face" or "Defrost" air without AC running and hotter than "Face" or "Defrost" with AC running depending on the temp setting dial. At least it felt so this evening driving in Boston traffic with an unusaully warm 45F external temp.

    2) Air that would NOT normally want or need humidity removed or cooling added isn't routed through the AC evaporator so it isn't preheated. I noticed the "Feet" blower was much cooler just as you did and the "Defrost" switch caused the same cooler air to blast above.

    The manual describes using the "Defrost/Feet" setting to de-humidify the air to the windows in order to clear fogging. And I definitely see the de-fogging of the windows happen when I turn on the "Defrost/Feet" setting with the AC running.

    Reading the Climate Control section of the manual does not clarify anything else though. I'm still confused about the "Defrost" switch, but it seems to only override the mode settings by design.

    Oh well, now that everything is clear as mud at least I'm not running my AC as much and the morning window fogging seems much better.
  • trispectrispec Member Posts: 305
    Hitting the published RX-8 numbers is basically just an exercise in restraint. My RX-8 AT with 7500 miles just hit 24.9 MPG. To accomplish this I did the following:

    1) I used full AT only, no paddle shifting, over a little 207 mile trip from Boston to Cape Cod National Seashore via Route 3 to 3A through Plymouth, up 6A, then back on 6 and 3.

    2) Through the little towns on the cape the speed was 20-40 MPH slow off season traffic.

    3) On the highway I never exceeded 65MPH and tried to stay close to the posted 50-60MPH speed limits.

    4) There was no punching take offs and RPMs stayed under 3000 over the whole trip.

    One interesting side effect of driving the speed limit is that you can always use the cruise control because no one else stays in front of you as all other drivers are exceeding the speed limit by 10 or more MPH.
  • ukjimukjim Member Posts: 63
    I think you are right (I think!).
    With the engine idling and the window open, I could hear what I assume to be the A/C compressor clicking on and the revs drop, when selecting feet/windshield and feet only. It would switch off when selecting feet/face or face only. Interestingly, the A/C light light does not come on on the mode switch.
    Bottom line, I have to run on feet/face when not wanting to run the A/C but want fresh ambient air. This is to my mind a major snafu, at night I want fresh air on my face, if I do that I get warm air that is either heated due to the air being sucked in from right over the engine or, it is being preheated by the heater core. So...I have to run the A/C all the time, not fuel efficient, and it has a noticeable effect on performance.
  • trispectrispec Member Posts: 305
    Have you noticed that the AC light seems to switch itself back on. I'm constantly having to turn the AC off. As for the fuel usage with AC off, it appears in city driving, AC costs at least 1-2MPG.
  • pathstar1pathstar1 Member Posts: 1,015
    Note that while you may notice a drop in fuel efficiency in the city, on the highway use of the A/C with windows closed will be more fuel efficient. Also, if you do not use "recirc", you are getting "fresh air".

    Intake air heating has been with the rotary from day one. We think (it's been discussed for years on end) it's caused by the engine being mounted so far back in the engine compartment. This heats the firewall/dash/console, above which is the air ducting.
  • mmadden1mmadden1 Member Posts: 17
    I've posted this on several other RX8 boards.
    Has anyone experienced a loss of power at highway speeds in 6th gear while driving at 65-75 mph?
    I've noticed this on several occasions while on cruise and starting up a gentle incline.
    The speeds drops off the set speed and setting on the accelerator has no effect. Dropping down a gear stabilizes the speed but nothing more.
    I noticed a thread on this on the RX8 club and some thought it was related to a stuck shutter valve. Any one here have a similar problem?
    ">link titlehttp://www.rx8club.com/showthread.php?t=52522
  • ukjimukjim Member Posts: 63
    Note that while you may notice a drop in fuel efficiency in the city, on the highway use of the A/C with windows closed will be more fuel efficient.

    Do you mean that it will be more efficient because the mechanical load on the engine of the A/C running has less effect than the aerodynamic drag associated with driving with the windows open? An interesting hypothesis, has this been documented? How far open does the window have to be open before it becomes less efficient?

    Or just that hwy driving will not be as inefficient as driving in the city? A fairly obvious conclusion irrespective of A/C use.

    Certainly any extra load on the engine cannot result in better gas mileage.
  • pathstar1pathstar1 Member Posts: 1,015
    It's been documented for several vehicles. I haven't tested the RX-8, but my Pathfinder definitly has less drag with the windows up. I tested it after reading in the owners manual that better mileage would result from use of the A/C instead of opening the windows. Now when decending mountain passes I open the windows to help hold the speed down. It works well, even though it's a bit noisy.

    It will not work in the city because the speeds aren't high enough for air drag to be much of a factor.
  • trispectrispec Member Posts: 305
    So my Group 2 2005 RX-8 AT has had a little noise since day one, which sort sounds like preignition only much software. It noise seems to exist at lowish RPMs.

    After months of searching online and after discussions with my dealer, there does appear to be some official confirmation of the sound by other owners of the RX-8 AT, but there does not appears to be any official response from Mazda.

    Some dealers say it's very bad and replacing the engine is the only fix. Some dealers says it's a bad fuel pump, but there are no fuel pumps available currently to replace it. Some dealers says it's just bad gas. Some dealers says it's normal, but they don't say why.

    My engine get 24.9 MPG on the highway and 14 MPG to 18 MPG otherwise. I think that millage is fantastic! I've never had a start problem nor a fading power problem at high RPM. And my RX-8 never produces the sound while revving the rotors in neutral.

    So does an automatic transmission have a normal little rattle sound at low RPMs? Is it some kind of normal slippage until it's spun up over 4K?
  • trispectrispec Member Posts: 305
    There's 8K on my RX-8 AT. Like to get this settled before 15K.

    What's so bad about a little bit of preignition?

    I can remember every car made had preignition knock from 1970's through much of the 1980's. The engine designs and unleaded gas additives got worked out. In 1979 I worked for a nutty guy who paid $700 to some guy to rip out the Cat converter just so he could run leaded (no knock) gas.
  • pathstar1pathstar1 Member Posts: 1,015
    Sounds like motor mounts to me. They are fluid filled and seem to be easy to damage during manufacture, as there were quite a few replaced. Have a dealer check them.
  • trispectrispec Member Posts: 305
    It's a soft sound, not at all like a metal on metal. Wouldn't a lot of vibration occur if a mount was bad too?

    I'll have them look on next oil change. Thanks.
  • trispectrispec Member Posts: 305
    Well, after three days of carefully listening to my little knocking noise I'm more and more leaning back towards minor preignition. Here's are the symptoms:

    On cold starts: 1) Tiny bit of knocking can be detected even with 2-3K revving while still in neutral/park. 2) On shifting to reverse, immediately a little knocking noise is there continuously. 3) Driving out of my drive way at home or the parking garage in 1st gear only, the knocking noise is there going up the hills or garage ramps, but the noise goes away going down hill or down ramps as I take my foot off the gas to coast down the incline. 4) On flat surfaces the noise comes and goes, but mostly seems loudest at low RPM acceleration.

    After warmed up: 1) The noise seems to lessen considerably, and is clearly gone for high revving or constant cruise speed driving. 2) Comes back very slightly once I return to low speed, low RPM driving in traffic and in my neighborhood. 3) Is not present when stopped and in forward or reverse gears. 4) Is not present when revving in neutral.
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