Maintaining the RX-8

Most problems that crop up in the 8 start very small and get serious because they aren't addressed. For example coils start going bad, plugs then start getting fouled from excess unburnt fuel, unburnt fuel rapidly degrades cat life, clogged cat can over stress the seals and over cook the O2 sensors, localize heat too much which accelerates oil breakdown and increases engine wear...

Most of the owners that remain trouble free are trouble free because they keep on top of their oil changes, their oil level, and their ignition health.

Then again, that stuff is like taking cholesterol medication and regular exercise for your heart. They help prevent problems, but it doesn't eliminate risk and it doesn't mean that you still won't die of a heart attack. Mazda factory QC over the engine tolerances has improved quite a bit, but it is entirely possible to be sitting on an engine waiting for any chance it can to fail. It's also entirely possible to completely ignore all the recommendations and get 160,000+ miles out of the engine (one new member to RX8club showed up thinking her engine was blown, come to find out it was just badly flooded, but she didn't know anything about rotaries and still had it healthy at 160,000 without doing what she should have)

It very is much like a heart, or lungs, or whatnot. All you can do is reduce the risk of failure.

Cooling and Lubrication are 99% of the battle to keep these engines healthy. Mazda didn't have enough of either from the factory, a flaw that puts us behind the curve. Several mods that are common can go a long way towards improving engine live. Namely the ReMedy water pump and thermostat, BHR ignition upgrade, COBB AccessPORT (for the part that allows you to monitor temps and set a lower threshhold for the radiator fans). Even removing the cat and going with a midpipe helps I think, as it helps keep heat away from the engine, and you don't have to worry about a clogged cat causing more problems. My engine was perfect until my cat failed, and it's never been right since. In spec, not replaceable point, but not back to the above average that it was. If you have a 2009 or newer, you have a Series2, along with the improvements to the engine that should mostly solve the lubrication problems. They still need better cooling.

But you also have the warranty. 100,000 miles, 8 years for the engine core. (if you are in that and outside powertrain, a "free engine" may still cost you ~$500 for all the fluids, gaskets, etc... associated with the engine, but not part of it)

Another source of problems is repetitive short trips, without getting the engine to temperature for at least a few minutes. Limited internal temp, and a proportionally larger amount of running time is under temp, increases carbon buildup dramatically, which leads to all sorts of further problems.

See the detailed articles on each of these major points, and others for more information.

(Updated September 11th 2014)