Ok guys this is the first Rotory I have ever owned and I don't presume to know anything about them. I have a 2004 RX-8 and it is the automatic tranny. When I crank the car sometimes it sits at 2k and takes a few min to get back down to 900 rpm's. When I put it in gear it sometimes runs a little ruff when im creaping down my driveway or street. Does anyone elses ride do this? Is it normal? Any help would be appreciated.

Sounds normal . Idle speed is increased when engine is cool/cold

What about running ruff? Should the cars idle be fluctuating lover then 900 rpm?

Same here.....

So this is the norm? Has anyone taken it to the dealer? If so what did they have done to it?

Sounds pretty normal for all cars, not just the 8. All cars have a fast idle / slow idle when they're cold and they warm up. As far as running rough... that's kinda hard to judge without the sound here. Ask the dealership to check it next time you're there.

Sounds pretty normal for all cars, not just the 8. All cars have a fast idle / slow idle when they're cold and they warm up. As far as running rough... that's kinda hard to judge without the sound here. Ask the dealership to check it next time you're there.


+1 :)

I misread your post when I originally replied.

When you first start up your car, the idle will be higher (usually 1500 - 2000 rpm range), after a few seconds, you'll see it start to drop till it settles just under 1000 rpm. This is normal, and the car will do it every time when starting when cold.

I don't know what you mean when you say it runs rough. Maybe try getting an oil change.

Ok guys this is the first Rotory I have ever owned and I don't presume to know anything about them. I have a 2004 RX-8 and it is the automatic tranny. When I crank the car sometimes it sits at 2k and takes a few min to get back down to 900 rpm's. When I put it in gear it sometimes runs a little ruff when im creaping down my driveway or street. Does anyone elses ride do this? Is it normal? Any help would be appreciated.

As for the orginal post, it would be normal for an RX-8's idle to be a little high at first (1k to 2k). It then comes down to around 800 to 1000 rpm after a couple of minutes.

It would NOT usually be normal for the idle to be rough, after the car has warmed up. This is when it appears to want to cut out and the car kind of rattles and shakes a lot.


Right now, I'm experiencing a rough idle problem that I did NOT have before.

I took my car in for an oil change. They had some Royal Purple oil so I decided to give it a try. It appears that I may have made a mistake by allowing a local grease monkey to change the oil vs myself, dealer, or a trustworthy mechanic. When I got the car back, the idle was rough.

I'm thinking the issue is a dirty MAF and/or dirty spark plugs. Possibly the cause was oil was over filled or they missed the hole and spilled oil somewhere. Also, I seem to be using more gas now too. Which also leads me to think its a MAF/spark plug problem. I made an appoint with the dealer to check this out and some other things I had talked to them about.

I'm interested if anybody else had a problem with a rough idle after an oil change. If so, than what did they do about it and what was the cause?

The rough idle might be the motor mounts, check the TSB to see how to check it.

I'm interested if anybody else had a problem with a rough idle after an oil change. If so, than what did they do about it and what was the cause?

Sounds like oil in your intake from filling too quickly . Check out this thread.

http://www.rx8club.com/showthread.php?t=105014&highlight=drinks