I had a very bizzare situation this morning on my way back from Boston. I was coming down the on-ramp and was getting on it a bit when at about 6000 rpm in 3rd gear the car basically fell on its face and I heard this loud rattle/vibration, which seemed to come from the exahust system. I continued to shift through the gears and got up to highway speed in 6th. The car was fine while crusing down the highway. However, I was able to reproduce the situation again after going through the toll plaza and again after getting off of the highway near my house in CT. It only does it in 3rd!

The stranger thing is that as I got closer to my house I stopped a couple of times and accelerated from 1st through 3rd to see if it was still doing it. It would NOT do it again!

I bought the car new about 3 weeks ago. It has 1200 miles on it and is scheduled for its first oil change on Tuesday. I'm going to ask the dealer to look into this, but wanted to see if you guys might have any suggestions or experience with this.

Thanks!!!

 

what kind of gas are you using?

 

Not sure what's wrong but I do know from experience that if the dealership can't recreate the sound you heard, they will not look for a problem. At least thats how my dealer is.

 

It's an 06, right? The spark plugs should be up to date, but they can get fouled at the dealership from test drives with people who don't know how to start and stop the engine properly.

However, this sounds more like a problem with the cat convertor, which is the weakest link of the RX8's exhaust system. It's also the lowest point on the car. Check it for damage and have the dealership look at it.

 

^ Yep, cat collasped most likey

 

New 3 weeks ago and now you have 1200 miles? That's like 400 miles a week unless your new car had a bunch of miles already on it.

 

My mom's new 06 Tribute has over 1000 miles in just under two weeks. Of course, she has been taking me to and from work since I still don't have a license plate and don't quality for parking rights yet. It had 117 miles on it when she got it although all of her paperwork stated it only had 7. Yet another one of our issues with that particular dealership illegally misrepresenting vehicle mileage along with numerous other wrongdoings.

 

hmm... was there any backfiring along with the rattling? when i first got my car it sometimes backfired very slightly after a cold start if i put it straight into reverse. i now warm it up 3 or 5 minutes and never have this issue anymore.

speaking of which, i'll be starting on my 2nd year of ownership in may. and, i just rolled over to 2100 miles on my way into work today. <LOL> wonder if the dealer will still honor my first free "3-month" oil change.

 

I get one every 90 days regardless of mileage. I could put 10 miles on and still get the oil change.

 

Yes, I realize it's a lot of miles for only 3 weeks. I don't see what that has to do with anything, though. I'm an attorney and do quite a bit of traveling around CT for meetings and court appearances. I bought the car in MA because I did a ton of shopping around. The car is an 05 and had 38 miles on it when I bought it. It is a grand touring and I got it for $500 under invoice. So the shopping around paid off.

The car ran flawlessly for 3 weeks and I broke it in properly for the first 600 miles. I have never redlined it. Actually, I've never even heard the chime at 8500 rpm yet. This is my baby and I plan on having it for a long time. I have owned several cars (and 2 prior Mazdas) and never experienced anything like this. So needless to say, I'm a little concerned.

I have been using strictly 93 octane.

I looked at the bottom of the car and there is absolutely no damage.

If that cat converter was collapsed wouldn't it make sounds in every gear and not just at 6000 rpm?

 

It sounds like the cat converter to me. I've had 3 replaced on my car in less than 2 yrs that I've had it. First one went after about one month of ownership. Thing I was looking for and you haven't reported is a Check Engine Light or, as it is known here, CEL. If it was the cat, one of these should show up.

 

Yeah, I haven't seen a CEL yet. Some guys on the other side suggested the cat too.

When your cats went did it seem like the car lost steam in the upper rpms? For some reason, it seems like my car doesnt want to rev freely right now. It seems to really drop off after 6000 rpm, even when it isn't as bad as the situation this morning. The rx-8 I test drove seemed to hit the 8500 chime with no problem. I mean, mazda put the chime there so people won't forget that they are approaching the redline since the car revs so smoothly and effortlessly. My car seems like it doesn't want to get past 7000 rpm. It will, but it doesn't seem appy about it.

Could this be the cat? Bad gas? If my engine runs fine otherwise, it wouldn't seem to be an engine problem, right?

 

I still think it's the DSC kicking in.

 

tell them to check your tranny fluid to see if there is any metal chunks in there. might be a poor tranny too.

when my tranny went out on me, 2nd, 3rd, and reverse made a clanking, grinding noise while driving. so check into it.

 

how long had you been driving it when it happened. and where you just cruising on light throttle before????


beers

 

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