Wej

I have a 2006 RX-8 w/ an automatic transmission and just a hair over 38k miles. Recently I have noticed that when stopped at red lights or in drive-thrus the car seems to be running a bit rough. At first it only happened when the air conditioning was turned on, but now it happens with it off as well. It gets smoother if I put the car in neutral and gets rough again once I put it into gear. I'm not mechanically inclined, I just enjoy the driving the car, so I am not sure what might be causing this. I don't want to take it into a dealership without at least having an idea or clue about what's going on so I don't get gouged $$$. It's 6+ years old now, I doubt any of the warranties apply anymore. Has anyone else with an AT had something like this happen? If so, did you figure out what it was and how to solve it?

Details:
2006 RX-8
Automatic Transmission
38076 miles (all mine, bought new from dealer)
91 octane fuel, always
Garaged nightly
Southern California, never cold enough to freeze
Battery is relatively new, bought it last summer (2011)
80% of my driving is city driving, I work less than 3 miles from home

Thanks

9krpmrx8

iTrader: (46)

When is the last time it had a tune up? Plugs, coils, wires, air filter, etc.

ShinkaEvo

iTrader: (3)

Motor mount.

Cliffjumper126

Probably is the motor mounts, unless the engine actually is misfiring at idle. Any CEL?

9krpmrx8

iTrader: (46)

Could be, pretty low mileage though for the engine mount to fail. But that is easy to check.

Wej

Thanks for the replies guys!

The last time I had it with the dealership, at around 29k miles, I was told that a tune-up shouldn't be necessary with that few miles on it. Maybe something has changed in the last 9k miles that requires a tune-up. I usually take it to a local shop for regular maintenance every 3500 miles or so. The dealerships are too far to go on a regular basis.

How would I check the motor mount? What is a motor mount? Is that where the engine is physically mounted to the chassis? I don't think the engine is misfiring. It sounds fine, it just feels rough. It still makes the nice smooth sound when accelerating, it's just at idle when I feel (not hear) the problem.

Also, I do drive it like a small sports car is meant to be driven. It may only have 38k miles on it, but it's on its 4th set of tires and 2nd set of brakes.

9krpmrx8

iTrader: (46)

Looks closely, the rubber on the top will be cracked or broken completely.

http://www.flickr.com/photos/9krpmrx8/8314731187/

04Green

iTrader: (1)

Suggestion. Clean the MAF, then look at coils. Grounds are not a bad idea either. DIYs are listed in the $100 thread in my Sig.