I have a 2007 rx8 with 75,000 miles. I've taken excellent care of the car. Oil changes every 3000 miles, my oil is still bronze...never turned dark. I burn 1qt every 3000 miles...dealer told me that was normal and not to worry about that even though the manual says every 800 miles. I replaced spark plugs, coil packs, and wires every 30,000 miles. I even change tranny and diff gear oil every 30,000. I was driving it last Friday night, I shifted from first to second around 4000 rpm and as I started to accelerate I lost engine power in an instant. The car started to stumble, check engine light flashing. I pulled over and it died. After thorough checking...I lost all compression on the rear rotor. I want to know what went wrong with my engine and how I can prevent it because I'd like to know what I was missing for this to happen. The dealership told me that I will never know because they just send the engine off to be rebuilt. Any opinions and suggestions will be greatly appreciated.

 

Did you pre-mix? What type of driving did it get? What type of oil and gas did you use? Did it get some de-carbon cleaning? If it is useing that little oil it could be it was not drivin hard enough. A/T or M/T?

 

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I premixed for the first 30,000 and noticed heavy build up on my spark plugs so I stopped premixing. The dealership has done all of my services and maintenance so my warranty is covered. I always checked my mileage and it's always been between 17-19mpg. I drive the car aggressively. I redline 5-6 times a day and shift around 4000-5000. I decarbon cleaned at 60,000.

 

the ONLY thing anyone can do to guarantee not having an engine fail is to never start the engine.

there is no valid evidence that doing anything (ie. premixing, sohn adapter, redline a day, etc) will increase the longevity of a renny. Yes, there is lots and lots of anecdotal evidence and there is nothing wrong with doing any or all of the ideas people have for increasing the life of your engine.

The best thing you can do is what you already were doing.

 

I've been thinking about something I read on Pettit Racing's website. Something was said about excessive rotor bearing wear and they suggested running thicker weight oil to extend bearing life. If I'm thinking correctly...if those bearing develop excessive wear then the rotors will oscillate more causing more pressure on the housing. Can that break seals or just wear them out quicker? And what are your opinions about that? The dealership puts 5w30 conventional oil.

 

I've taken apart a motor or two here and there and I've NEVER seen any significant rotor bearing wear.
At worst, there is occasionally some wear of the front stationary gear bearing, but that isn't going to contribute to seal stresses much.

Laythor hit it on the head - it is a crap-shoot.

Just keep doing what you did and cross your fingers.

 

I'll keep doing what I'm doing. Thanks for the input guys...I needed it.

 

My 07 uses even less oil-1/2 quart per 2k miles, and I've always premixed Mobil 2t about 1/2 oz per gallon.

With such low oil use on op's car and mine, I can imagine the apex seals wearing fast without premix.

Oiled plugs or not it's gotta have seal oil, and the GOOD COILS wouldn't hurt.

 

It sounds like you had a catastrophic failure. Most of the things I know of that people do help prevent slow compression loss.

 

you dont....

Sorry, there is no sure fire way. people can sit here and spout use oil X, pre-mix with Y and blah blah blah, but really, in the end, those suggestions may or may not really help in the end.

 

Pray every morning when you wake up and before you go to bed. Thats the best way to prevent engine failure.

 

That's what I was thinking. Something seriously nasty happened all at once, different than the usual slow of worsening symptoms.

What to do though? If you read around the website, you'll find lots of suggestions and educated guesses, but it seems you can always find someone who's engine failed while doing <insert variation of maintenance routine here>.

About the only thing I'm going to do differently with my "new" engine is have Mazda do that "decarb" thing once a year. No proof it matters at all, but just an intuitive guess.

 

Yep, he said it best. Some of us have done just about everything you can and still had failures despite premixing, SOHN, oil choices, OCI's, driving habits/methods, etc. Just change the oil, follow the factory recommended maintenance, and don't bang on it cold, you should be good.

 

luck of the draw--engine is a flawed design for the amount of output its asked to do.
However on the flip side--friend of mine that runs a jam up garage has posted a picture of an rx8 with 200K miles on the oridginal engine. believe it or not. No mods on the car. Owner said "Just drive it".

 

• Are you adding anything besides gasoline to the fuel tank?
• Have you modified the engine or its oiling system in any way?
• Are you using an oil other than 5W-20 non-synthetic?
• Do you pull away before letting the engine warm up a bit?
• Do you rev the engine above 4K before it's fully warm?
• Do you fail to rev the engine to redline regularly?
Seems like most of the folks here who've had engines replaced answer 'yes' to at least one of those questions.

Draw your own conclusion.

 

Search around......there is even some debate as to whether or not you should even do a decarb that often.

 

Ever overheated ?

 

• Are you adding anything besides gasoline to the fuel tank? - yes
• Have you modified the engine or its oiling system in any way? - yes
• Are you using an oil other than 5W-20 non-synthetic? - yes
• Do you pull away before letting the engine warm up a bit? - yes
• Do you rev the engine above 4K before it's fully warm? - no
• Do you fail to rev the engine to redline regularly? - yes
Seems like most of the folks here who've had engines replaced answer 'yes' to at least one of those questions.Almost 70,000 miles on my 2005 RX-8, original motor, I consistently dyno higher then the vast majority of people here who are NA., and the car still runs like a CHAMP. No motor issues here...


Draw your own conclusion. - I've drawn MY conclusion.



just because YOU keep blowing them up OD doesn't make the design flawed.


all the silly theories aside, Laythor said it best: it's a crap shoot. If you want to never lose another motor again, it's easy... never drive the car.
All motors will at some point fail, some pre-maturely due to no fault of your own and other fail due to negligence. Just take care of your car and it'll take care of you.

 

With all due respect, no. But I like how you quietly slip it in there as if it's fact. If you ever go into journalism, I know a network news organization who'd love to have you.

 

But you have the "force" !

 

not my fault you guys are but mere mortals.



besides, you have Brettspeed...

 

True - just think what we could do if we combined the two muhaha muhaha !!!!

 

Maybe we'd get our ***** avatar back?

 

"Strange game...........only way to win is.............not to play".
"How about a nice game of chess"?