vspecpgt

Hi,

Just wondering what was happening to the certain RX-8 Engines that were failing, and being replaced under warranty.

I've got an FD and understand quite well how motors blow etc, however with an FD it really only happens with detonation or overheating.

I did a search on "engine Failure" but could not find a thread relating specifically to the cause of the failure on the rx-8s. The only thing i have heard of NA rotaries, Mostly from 12a and 2nd gen guys, is that they last forever.

What went wrong in those cars that needed new motors? Bad part? busted omp? bad interal seals?

Also, i'm buying a 2004 at the end of the month, so i'm just reading up a bit to get familiar with the car.

Thanks

Harrison

shazbot28

iTrader: (2)

It has to do with the seals. When you bring in the 8 for the engine recall test, they do a vacuum test on it to see if there's any leaks.

eviltwinkie

Mainly because when you masterbate...god kills a rotary...

Nemesis8

iTrader: (3)

And you'll go blind

Jax_RX8

To meet emissions, the OMP oil injection rate was not high enough causing too much apex and side seal wear eventually reducing compression below normal operating limits - causing the need for an engine replacement. Some cars also had issues with Catalyst clogging (caused from incomplete combustion due to the low compression) that exacerbated the problem.

Most with this issue tended to be in very hot climates, some had extended idling situations, and some drove the car too conservatively (with the last two not injecting enough oil in low rpm/low load situations).

The latest recall included a check of the engine compression, catalyst, and new fuel/OMP profiles to increase the oil injected at idling, lower rpms, lower loads.

BUT, many still think the additional lubrication is still not enough as they still have to meet emissions with the engine. Thus, they "Premix" to add additional lubrication via the fuel. There is a very long sticky thread dedicated to this subject that you can read to make your own determination on whether or not to premix.

I and some others here have added the Sohn OMP adapter to allow the feeding of 2-cycle oil to the engine instead of sump oil - providing better and cleaner lubrication of the apex and side seals while minimizing catalyst clogging.


Before buying any used RX8, I would recommend making sure the 4206F recall has been performed to assure the engine compression and catalyst are OK (they are checked as part of the recall).

Red Devil

LOL, I was just about to write this line.

vspecpgt

I'm surprised to read that many people think it still wouldn't inject enough oil. I know the 8 has 2 injectors per housing vs the 1 on the FD. They did it to lubricate the housing more evenly than on the older styles. I do a bit of premixing on the 7... but not very much... about 4 oz per fill up.

Anyway, the car i'm buying is an 04, but has had no problems whatsoever, and has had all the recalls and TSBs done. Looking forward to picking it up. It will definitely look a lot more sporty than my wrx.

Phantom Menace

Old Rotor

I know the amount of engine problems are inline with the norm. I just wonder if the rest of the world is haveing the same engine failures as the US? Or is it our emissions that are the problem.

puch96

Well, I guess if that is the case, get a buddy overseas to send you an ECU reflash and you'll be all set

nycgps

iTrader: (1)

its not going to work with our US spec 8.

Gambit

at least the kittens are safe now

Nubo

From what I've ready, for the majority of failures you'll never know the exact cause because the dealerships don't tear down the engine. It's crated and shipped back to Japan or to a reman center where all traces of sin are removed.

Silvermister

I think its the radiation from Hiroshima sticking to our apex seals.

nycgps

iTrader: (1)

lol

but we threw the bombs right? so are we backfiring ourselfs now?

nycgps

iTrader: (1)

As far as I know most of the failed engines came from the North America's market.

IMO : Mostly due to the 5w20 oil that Mazda *recommends*
Notice : thats what FORD recommends, because by doing so, they can have better *looking* emission numbers.

It seems that Mazda *forgot* to re-adjust the OMP rate for the 5w20 oil, engines did not get what they really *need*. so eventually they will fail. They re-adjust the OMP rate after the recall flash, so it should be fine now. Just have to wait and see.

When I was hmm 8K miles? I switched from 5w20 to 5w30, Royal Purple.

and I dont think it has anything to do with the 1 oil cooler thing, they have 1 oil cooler everywhere. no one seems to have a problem as much as the N/A market does.

hayasa8

I have to believe it is a heat issue from the cat and peripheral port...old na cars were quenched by cats...I put 160,000 on my FC (88 rx) and drove it like an angry teenager...what ultimate killed my was side seal failure from over revving. (one of the original rotary masters in San Dimas, CA told me that by hitting the rev limiter the eccentric shafts harmonics would cause the rotating assembly to lurch transversely to its spin, then put in a lift and had me watch the crank pulley, he was right) old 13b's had a solid surface side plate as opposed to our peripheral port design...I think if we dismantled ours we'd see some out of plane issues with our side plate issues and lots of dried out apex seals and uneven side seals...and btw I ran at least 10/40 in my FC usually running 20/50...wonder if I could still do that?...does anybody know...searching, as opposed to hijacking the thread...

Phantom Menace

...because this thread fails...

vspecpgt

How about you fail on posting. this is supposed to be a technical forum/thread. your posting does nothing except make the forum slower.

Nycgps,

I wasn't talking about the oilcoolers. I beleive all the rx8's come with two, vs the latest rx7, where as only the R1 and R2 packages came with dual oil coolers. I was at speedsource a while back, and the rotor housing itself has two holes to inject oil per housing, vs the FD and previous designs that only had 1. So i was surprised it was premature apex seal wear.

Regardless, still looking foward to picking up the car. Mazda still using Dino oil? My FD has only seen 20/50 syn.

Phantom Menace

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nycgps

iTrader: (1)

I thought u are talking about oil coolers, u're talking about the injection.

but still, not all RX8 comes with 2 oil coolers.

the premature wear was caused by Mazda, they didnt get the OMP right in the first place.

Mazda dont care about Dino or Synthetics, its just their business practice. Its easier than say no to all than testing them all. I use Synthetic and I have no problems with it.

lone_wolf025

So based on the assumption that oil is the main cause, possible solutions would include slightly heavier oil, and/or OMP "upgrades"

MPG > HP

So oil viscosity has no impact on OMP performance, regardless of tuning? Wouldn't a lower viscosity oil flow more freely or it's all about OMP tuning that determines how much oil flows, regardless of viscosity? If the latter, then other than getting the correct flash, we are on our own to make corrections via pre-mixing, alternative OMP feeds, etc?

Jax_RX8

Correct

No - OMP controls flow rate independent of viscosity. Some prefer higher viscosity for thicker oil film after injection.

Correct

Another alternative to premixing is you could get the Sohn "Adjuster" (even without the "Adapter" to change the oil source) and use it to manually force the OMP to a higher "base" flow rate (would be no longer based on load). This higher "base" flow rate would then be adjusted up to the maximum flow rate via RPMs.
Details here:
http://rotaryaviation.com/oil_inject...p_adaptors.htm