My wife purchased a 07 RX8 about three weeks age. The first week everything seemed fine. All of a sudden she started getting a vibration that feels like the car is bouncing. After I test drove it, I was easily able to duplicate the problem by bringing it up to about 60 mph and slowly taking it down to about 45. Watching the gear indicator the transmission remains in 6th gear. While slowly accelerating, at about 50-53 mph the car starts to violently do this vibration/bouncing, almost like you have square tires. The whole time this happens, the car is in automatic. The vibration stops immediately if I put it into manual and down shift to 5th or give it a lot of gas and then it will down shift to 4th or 5th. So we brought it to the dealer and they first claimed they were unable to duplicate the problem, then said my wife was not driving it aggressively enough, then they said it’s probably bad gas. Three tanks of premium gas later the car still does it. Has anyone experienced this? This can’t be normal is it?

 

Sounds like you are "lugging" it; manually shifting it will allow you to lockout 5th and 6th gears.

 

It's the engine lugging. I guess ATs + rotaries just don't mix very well as you're more likely to feel lugging due to the low torque rotaries have, at least with the generic AT shifting logic that's been stuffed in. Rotary ATs really need to have their shift points readjusted so that the car cruises at no less then 2800 RPMs or so ideally, otherwise lugging will occur if you don't give it more gas. Which isn't something you can always do when you're practically bumper to bumper with the car in front of you. I drive mines exclusively in manual mode just to avoid the lugging, and because the car is an absolute slug in 4th (04 model) while running around town. Driving it in full auto and driving it in manual is like driving two entirely different cars.

 

If it's in automatic mode, it should... guess what? automatically downshift. The dealer is throwing him BS, I would find a new one.

 

OK. We brought it back to the dealer and this time I drove the service manager in it and duplicated the problem. The next morning I got a call and they said there is a service bulletine on the problem and it's with the harmonic balancer. He said that the fix is to replace the engine! The car is only three weeks old and only has 3000 miles on it! The new engine is on order and will be replaced once it arrives. I can't find any information on this problem any where.

 

Interesting. I'm going to look into this.

 

HuH !?

Are they sure about it ? Jesus christ you having some bad *** dealership. Oh make sure you're getting a BRAND NEW ENGINE. and NOT a Reman one ... Cuz thats what you deserves.

This is actually the first post I see about the 6 speed auto.

 

I just bought an 07 AT, it has less than 500 miles on it. I have had it about 2 weeks. It is doing the same thing you described. When I am cruising about 50 mph, it can't seem to chose which gear it wants to be in 5th or 6th, it vibrates or bumps until I give it more gas. It then picks a gear sometimes 4th but once I try to maintain 50 again it repeats the same problem. I haven't driven my car too much yet (just noticed it really today) so I don't know how often this will occur. But I wanted to say it has happened to me. (I think the same thing).

(I just realized this thread was really old, sorry). Whatever happened???

 

Just wondering why a bad harmonic balancer would require an engine change. Doesn't sound right to me.

 

I just got my 2007 RX-8 a week and a half ago and I am having the same problem with 6th gear at around 80 kph (50 mph - I am Canadian). As I cross 80 kph in automatic mode, the car begins to shudder like crazy as if it is on a bumpy road. When I slap it in manual and try to do the same thing I can't get it to happen.

I'm guessing that it is the computer constantly wondering if it should engage the clutch and switch to 5th since the revs are so low. I'm taking the car in next week to get the performance package they ordered for me installed. I'll bring it up and see what they say.

 

Sounds like your "wife was not driving it aggressively enough" is what killed the engine with carb build up being a bad thing for Rotary cars and to cover this up theyre just saying bulletine and harmonic balancer.
FYI you have a AT drive it in sport mode and rev it to around 5-6k every day or everyother day.

As for the vibration/bouncing thing, thats what happen to me on the freeway going home from the dealer right after the service manager just told me your car might need a new Engine.
Then my car dies on the side of the road gets towed back to the dealer where he shows me a paper saying oh yeah here it is, your car is due for a new engine.

-Gil

 

I have a 2004 Automatic tranny. I started the other day and I had no power in first. When it shifted into 2nd @ 30mph it was like I slammed on my brakes and dropped down to 9mph. It will then drop into first and do it all over again. It nearly throws me throw the windshield. If I but it in manual mode, 1st is like park. To drive it I have to drive it in auto and when it gets to 2nd gear hurry up and put it in manual mode and upshift to 3rd. 3rd is the only gear that drives right but if I slow down it will go back down to 1st and lock the wheels up. It is awful. Has anyone else had this problem?

 

^^ No, but I would definately get that checked out.

 

I have an 04 AT and have the same problem everyone else is saying. It is really starting to get annoying that I always have to change to manual if I want it to change gears faster instead of getting stuck. I am pretty sure the cause of this problem is Mazda's ecu programming. Has anyone gotten their ecu tuned to fix this problem by increasing the lower revs?