Originally Posted by RIWWP (Post 3663965)

The engine failure story:
Most of the engine failures were on 2004s with automatic transmissions. The 2004s in general had more issues due to the flash not adding enough oil and a few other things off the boat, and the automatics being 4-port and usually driven much more casually compounded the problem.

Compounding THAT was the original reman facility for the engine replacements did not have very good quality control, and alot of those original reman engines had improper seal clearances and other build issues that caused quite a few people to get to their 3rd or 4th engines.

MSP-16 updated the flash and improved things greatly, and happened early 2005. Mazda North America can tell you if MSP-16 was performed for any 2004 or 2005 if you give them the VIN. they also re-vamped their reman facility, and reman engines 2006+ are now usually far better than the original factory ones. So if you find a 2004, 2005, or 2006 with an engine replacement that occured late 2006 or later, don't take the engine replacement as a negative mark against the vehicle, but a positive one, as it means the engine is likely in fantastic shape, and good for quite a long time.

Plenty of 2004s were still perfectly fine.

2005s have a much reduced failure rate, 2006 further, 2007 and 2008 are relatively rare.

In 2009 they introduced further engine changes correcting several things, the most critical of which was an increase in oil pressure to RX-7 ranges (they dropped it for the 2004-2008 years for some reason), and re-introducing the center oil injector (they deleted it for the 2004-2008 RX-8s for some reason, all prior rotories had it).

I have not heard of a 2009+ engine failing yet. That doesn't mean that they won't though.

A compression test should be standard before anyone buys an 8 though, just to be on the safe side. Most dealers charge $80 to $120 to do a compression test.

General issues to keep in mind:
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 owner came on here 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" will still cost you ~$500 for all the fluids, gaskets, etc... associated with the engine, but not part of it)