l have a 2004 Mazda RX-8, l bought it used just a few months ago. Ever since l got it, whenever l start the car and if its sitting idle, this ringing sound starts up from the back of the car and the car shakes. What is causing this?
It runs fine and all, but the noise and shaking bothers me.

how about walking around it while its making the noise and listen

Have u been following the proper maintenence procedures? Warm-up is MANDANTORY for a rotary engine. Give it 10-15 minutes on every cold start & it will reward u by lasting forever. My grandpa had a 1974 RX4 & drove it daily up untill last december, selling it at 375,000 miles with no rebuild or anything. Take care of ur engine, & it will take care of you!

When it shakes like that, is it bogging down, or about to stall? Rotary engines r finicky at times, especially when they're not ready to go. That RX4 would stall out every time if it was not warmed up, sort of an idiot-proof feature.

Rotary engines use oil, at the rate of about 1 quart per 3000 miles, dependon on how u drive. And remember to redline it once a week to clean out all of the carbon build-up. For more info, be sure to go to rx8club.com or its sister site rx7club.com

-Takahashi Ryosuke