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Mazda RX-8 Problems and Solutions



  • pathstar1pathstar1 Posts: 1,015
    That "halting vibration" could be the DSC operating the rear brakes to stop the inside wheel from spinning. It could also be the rear diff., though it wouldn't produce any smell. It may be a combination of the two.
  • trispectrispec Posts: 305
    Have not seen the DSC light blinking. Does Lim Slip Diff work on a mechanical level with heat playing a part?

    Well I'll give the "halting vibration" a testing in the winter. DSC and Lim slip Diff should get a working out in the snow and ice, although I was hoping to keep the RX-8 out of the really bad stuff. Then again, Boston's Mayor Manino live's in my neighborhood, so snow removable receives prompt attention usually.

    Thanks Pathstar
  • pathstar1pathstar1 Posts: 1,015
    The limited slip is a mechanical device with no electronics in the loop. It is subject to temperature in that the diff. oil is very thick when cold and not so thick when hot. Diffs. do run at fairly high temps. once warmed up, but only when they are handling a lot of power.
  • trispectrispec Posts: 305
    pathstar1 said "Diffs. do run at fairly high temps. once warmed up, but only when they are handling a lot of power."

    OK, then the vibration in the rear must be the LSD cutting in. I was driving this morning and hit a wet patch while in a traffic rotary uphill, turning, and accelerating. The backend started to slide, the DSC light flicked on, and she straighten right up instantly. There was absolutely no vibration. Lots of fun that was.

    Then I was at a stop sign shortly after that DSC event, turning hard right and accelerating. The vibration as if from the inside rear was fair intense and no DSC light. Then I smelled a faint clutch burn.
  • pathstar1pathstar1 Posts: 1,015
    If it is the LSD it should smooth out as you get miles on it. Like any mechanical device it has to "wear in" or self machine the internals. I still don't know where the clutch smell is coming from. The LSD is sealed (except for a small vent valve on top) and the clutch plates in LSDs are immersed in oil so no smell there. I suspect it's the rear brakes (DSC). If you want to verify further, turn off the DSC (hold in the button as per the owners manual), then try it. If you then get no smell then the smell is from the brakes being activated by the DSC. It may be it operates so fast the lamp doesn't have a chance to light. I presume you are "goosing it" when this happens.

    You can turn the DSC back on manually, or it will automatically come back on the next time you start the car.

    BTW, even turning the DSC off this way it isn't really all the way off, just being told to "relax" by the PCM.

    Also, the above "self machining" produces a lot of metal "bits" in the transmission and diff. oil. It's a good idea to have the oil in them changed after about 20,000 mi. I like to use "Royal Purple" - it's synthetic so should reduce frictional losses and it works well with LSDs (no additional additive needed).
  • trispectrispec Posts: 305
    Actually, I think it is getting smoother, but the halting vibration is still there when I do a semi-fast take off. I never floor it, but it's a nice strong take off.

    I'll try turning off the DSC to see if the clutch burn smell goes away completely.

    At 20K miles I'll look up this conversation for the Royal Purple brand. Thanks.
  • Thanks for the reply, I'll keep it revved as much as possible. Have you ever heard of a problem like mine? I just don't want to find out in a few months that I've purchased a lemon.
  • pathstar1pathstar1 Posts: 1,015
    As I said earlier, there were a few engines that were assembled incorrectly or the parts were machined incorrectly. It's not common, but we hear from the owners (as we should!). My friend was one. His has been fine ever since the engine was changed. Once the engine is replaced they have been happy. You will find the rotary engine will last a long time (previous normally asperated - non-turbo rotaries went well over 200,000 mi.). Just make sure you keep an eye on the oil level (check every two or three fillups) and don't let the coolant get low and you'll be fine. The engine injects oil from the sump into the intake (part of the design) so it does go down slowly. Most find adding a quart after 3000 mi. is normal. Some are able to go all the way to oil change time.

    While there have been RX-8s with problems, it's not common, and they are usually fixed and don't recurr.
  • Some sort of vacumn leak around fuel cap is causing my yellow engine icon to display....these new fangled cars! :P
  • I have now owned my RX-8 for 5 months (bought new in June, 6-speed manual) & I am amazed by the number of posts reporting problems.

    Maybe I'm the exception - I hope not - but I've never gotten less than 18 mpg (mostly around-town driving), and a consistent 23 mpg on the highway. No brake squeal, no power lag, haven't needed to add oil yet (granted the car only has 1200 miles on it), nothing to gripe about (my other car is a Lexus ES & that car made me picky since they're bulletproof) but I can honestly say I've experienced no problems.

    At various message boards I've seen it posted a number of times that the problems are more prevalent on 2003-2004 models. I'm no mechanical expert but I've read that there have been a number of modifications to the 2005s to improve gas mileage, reliability, etc. I tend to shift around 3500-4000 rpm and always use super unleaded gas.

    OK, one gripe - I wish Mazda would have made the back seats fold down for easy access to the trunk. But - that's it, and I hope things improve for all those who have has problems because I'd hate to see Mazda discontinue production of the car - I love it! Velocity red, Grand Touring Package, rear spoiler, chrome wheels make me smile just to look at it.

    Better luck with your cars everyone! Flip
  • I have a 2005 6 speed. I took it in today for snow tires (Bridgestone Blizzaks -- I live in Pennsylvania). I also had an oil change. The service people at the dealership replaced the oil with 10w30 grade. They told me that there has been a factory notice that with the higher engine revs and temperatures, that they were having problems with the rotor seals with the 5w20 grade oil that had been recommended in the manual. Has anyone else heard this?
  • trispectrispec Posts: 305
    What were the Blizzaks running you. I'm thinking about a set.

    By higher revs, I'm guessing this is the manual 6 speed, versus the auto.
  • It is the manual. The Blizzaks were ~$230 apiece (ridiculously expensive), but if they get me through the winter, they are worth it, as I have no other car to drive. BTW, I love this car.
  • I'm in New York City metro area, going into my third winter with the Blizzaks. I pass by 4wheel, all-wheel etc. that are stuck in the snowbanks because they skidded off the road when going around a curve or while braking. All wheel drive might help you get up your driveway or some hills, but it doesn't prevent the skidding mentioned above. Use real snow tires on all four wheels, common sense, and if the snow isn't higher than the underside of the car, you should be ok
  • trispectrispec Posts: 305
    I'm thinking about some Avon all season performance over the strict snow tire like the Blizzaks($198each). has the Avon 225/24 18 for $135 each for ultra high performance. The Tirerack guys said using any winter performance tire in anything but winter weather wears them out really fast.

    It's not like I'm gonna race'm in the snow if I get the Avon all season, but I would not like to constantly be changing tires for the seasons.
  • I believe that you're in the Boston area so you can get some nasty snow. I assume that your RX-8 came with the summer only Bridgestone hi performance tires. If you are not replacing your summer tires with the all-season Avons as your only year-round tire, I still suggest that you purchase the Blizzaks, Dunlops, Michlein etc. true winter tires on the least expensive wheels that the Tire Rack sells, approx. $130 ea. The Tire Rack does an excellent job of mounting, balancing and safely shipping the tires and wheels right to your door. I've dealt with them 5 times already in this fashion. My Blizzaks don't appear to be wearing out anytime soon, are quiet and handle pretty darn well. Having the two different sets of tires mounted on their own wheels makes changing tires a snap and assure you of the best opportunity of not getting stuck in snow and ice.
  • trispectrispec Posts: 305
    A bit more info on Boston and snow. We can get wicked, 30" to 50" inches accumulation. But the snow clearing on the roads is legendary. Also Boston's mayor lives in my town so clearing out our direction is extra diligent. They've always jumped on the street in front of my house for the last 15 years clearing non-stop during the storms. There's also city snow equipment depot two blocks away.

    We would never have to drive on very much snow if any so thats why the all season tires are under consideration. There's also a front wheel drive with traction control second car that's for the really bad days.
  • Has anyone else been informed to go to a heavier grade of oil? My Mazda dealer informed me that rotary heat and high revolutions necessitate this change from 5w20 to 10w30.
  • I haven't heard anything about Mazda recommending 10w30...I just had an oil change 11/14 at Mazda, they put in 5w20...

    Am I the only one who feels like their dealer is flying by the seat of their pants with RX8?
  • My Mazda dealer actually used 5w30 last time I had the oil changed and made the comment that Mazda said it was "appropriate for our climate" I have noticed a small drop in gas milage. I even contacted Mazda about this, and they emailed me back saying that it was OK for my area of the country. ( North Carolina, USA.)
    I have wondered about my dealership at times. I guess the upside of using the dealership for oil changes is that they have coupons available for $15 bucks for an oil change.
This discussion has been closed.