Is this rattlesnake sound normal?
 

My car makes kind of a rattlesnake sound. This is my second RX-8, with a 9-year gap between them. It's been a while, but I don't remember my first one sounding like this. But maybe it did and I just don't remember...


The sound of my radiator fans is also quite prominent in that video, but you should be able to hear the rattlesnake sound I'm talking about.

Thanks! I had the car up for an oil change today and so I took a look from below, and the rear 2 spark plugs were crooked. I pulled them out and put them back in straight, and torqued them to 140 in lbs with a spark plug socket. Still getting the rapid "tsss tsss tsss" though, so I'll pull and re-torque the front 2 spark plugs next. Have also been getting misfires on the rear rotor, so I plan to swap the back coils with the front coils to see if the misfiring rotor changes (thanks to Loki for that idea).

Yikes, that's no good. The previous owner had them in that way (I bought it a couple weeks ago), and I'm not sure how long the rear rotor has been misfiring. If the housing is damaged, I'm assuming that's why I'm getting misfires, and that'll lead to unburned fuel in the cat, which will lead to a clogged cat, which will lead to an overheated engine. Am I right? Anything I can do now to mitigate damage to the catalytic converter?

The misfires were happening almost every time on startup, as well as when hitting about 7,000 RPM in first gear. After straightening out the plugs, they only happen when hitting about 7,000 RPM in first gear. Maybe I should just avoid going over 6k RPM in first gear?

I bought it with the assumption that it'll need a rebuild in the next year or two. I'm hoping to get at least a year out of it, but I also don't want to destroy the catalytic converter in the process.

Thanks!