^

Truth in perspective.

 

We know the failure rate for the Shuttle but, unless you have numbers I haven't seen, we don't know the replacement rate for the Renesis engine. Every number I've heard is pure conjecture. Would love to see your data.

 

Papers? I must have missed those "papers". Do please post a link! And isn't it funny how in every road test and article about the SII in all the major auto magazines, there's no mention about Mazda ******* up. In fact, there's nary a word about engine tweaks. The articles detail changes in suspension, grille, taillights, fuel capacity, etc. – but barely a mention about changes in internal oiling design.

How odd.

 

He said that the Renesis has more than a 2% failure rate. As in they fail more than 2% of the time.

I don't think you would argue that point.

 

All New Yorkers, not just the above, NYCGPS, and myself included, argue about every damn thing on the planet, regardless if there is a point in making the argument.

Its like a sport to us.

Its one of our endearing qualities, that others "love" so much.

BC.

 

Yeah, I work here now, so I'll argue anything

 

I did say "bandied about."

FWIW, it's possible to piece together rebuild production rates from odds and ends on this site (like SleepyZ's posts), then divide by RX-8 sales. But I'll leave that calculation to others.

Ken

 

My engine lasted 73k. But didn't die a slow death. Literally felt great and took off fron the next stop and apex seal shattered at about 4k rpm. Now im just over 1k miles on the new engine. Runs great

 

Good I was just worried! haha That 11mpg really freaked me out!

 

I've got a bit of a better track record that the post 2 above me...

4th engine, roughly every 30k...

OE engine was toast @ about 36k, only the last 9k were by me, the second owner. compression issue

first reman was pouring in 1 quart of oil per day into the front rotor... that was not cheap cause the 8 is my daily driver..... replaced at 60k

second reman was showing increased oil consumption, and after an oil change, had low 4s on the front rotor, and high 8s on the rear rotor.... not a good sign either. Just replaced today, @ 87k

Just got my car back today, feels nice and strong, but with my second kid on the way, and not many options as far as my car goes, it looks like I will be trading it in... makes me sad, but it makes more economical/safe sense. I love my 8, but its not fitting in my life at the moment, and wont for a bit. When I get more disposable income, I will get me a used 7/8 and make it my project car

 

 

My engine replacements have been free. Last one, I replaced the plugs before I brought her in for the compression test... forgot to add that :D

 

2004 RX-8: at 40K dealer thought compression was going - had to replace coil f r $600 -rest ($6K engine) was free.

 

Well, I too don't think that this is 100% true about any car, not only about RX8 as it totally depends on the way one maintains the car and its engine. Otherwise, there is the possibility of anything.

 

rx8whitten and getemslough, I moved the posts regarding the Pettit S/C car out to it's own thread in the Major Horsepower Upgrades subforum here: https://www.rx8club.com/major-horsep...ngines-238522/

If you are looking for advice and troubleshooting help, I highly recommend you continue the thread there with greater detail than you have provided so far.

 

I believe mine MAY have been replaced once and I'm almost at 60k but I don't think it has. I have only drivien it like 1500 maybe? and i've had no problems, my daily driver, I hand wash it, and I plan on changing air filters and such myself when I get the money.

And if you read the manual, and follow it, much will go well with you.

 

I'd love to know the precise failure rate.

This is just a SWAG, but I'd place it between 10% & 15% within 100k miles.

If so, that'd be pretty high by relative standards. I'm sure many people will claim that's actually a conservative estimate given the noise here and elsewhere, and they may or may not be correct, but as in all things catastrophic failure, anyone who has one is FAR more likely to post about it versus those who have not.

From a legal, technical standpoint, Mazda would probably be compelled to disclose the % failure rate via the rules of legal civil procedure & discovery, and any attorney worth his/her salt could also probably ensure to preserve a legal record whereby it would be reversible error for a court to disallow introduction of said % failure rate into evidence at any court proceeding (i.e. a trial).

 

It is my experience and observation that 80-100k is about the life expectancy of an all original rx8 engine, unless exceptional circumstances occur to push the failure sooner or later. For example, routine coolant flushes, dedicated use of premix and heavier weight oil might allow an original engine to go 120-160k, while being overly babied/carboned up with poor oil change habits and no maintenance could cause issues as early as 30k miles.

And yes, older rotaries used different placement and numbers of oil injectors.

85 and older engines used a mechanically actuated OMP with 4 lines and 4 injectors, 1 per rotor housing in the center and 2 in the primary intake runners.

86-88 engines used a mechanically actuated OMP with 4 lines and 4 injectors, 1 per rotor housing in the center and 2 in the primary intake runners.

89-91 engines used the same setup except with an electronically controlled OMP.

93-95 engines used the same type of OMP but now only 2 lines/injectors, 1 per rotor housing in the center.

04-08 rx8s used an e-omp with 4 lines and 4 injectors with injectors at the corners of the rotor housings.

09+ rx8s added an extra set of lines and injectors to the center of the rotor housings (3 per housing).

Notice that with each change, longevity of the engine seemed to be reduced. I don't think it's a stretch of the imagination to think that this is because of reduced lubrication via the OMP.

The 1st gen rx7s could last 200k or more routinely. They were notorious for burning a ton of oil, the OMP was set to inject a lot of oil so the seals got lubricated well.

The early 2nd gens were almost as good, but average longevity did drop 25-50k miles vs the 1st gens.

The later 2nd gens introduced the electronic OMP in an attempt to more closely meter the oil and reduce emissions...in other words they turned the OMP injection rate down. And guess what? Longevity dropped another 25k miles or more.

Then you have the FD. They came out with a "special" coating on the rotor housing chrome surface that they thought would reduce the need for OMP injection. So this is why they only did 2 oil lines and injectors. But, the coating must not have been as good as they anticipated, because those engines wear out at 75-90k on average. Of course, these are boosted engines that were set up to run 12psi and then detuned to 10psi and sold that way, so they ran near the edge all of the time...not all of the engine's premature death issues are OMP related.

Then the rx8 comes out, and they go back to 4 injectors. So you're saying to yourself...why don't the rx8s last longer than the older engines, if they have 4 injectors? A few reasons, in my opinion:

1) although there are 4 lines and 4 injectors, the e-omp and pcm are still in control of the VOLUME of oil that flows out. And to meet emissions they had to turn the OMP injection rate way down. You can have all the lines and injectors in the world and they won't do you any good if a minimal amount of oil is allowed to flow through them.

2) the position of the injectors in the corners of the housings prevents oil from penetrating to the center of the housing and seal...and so the center tends to wear more than the edges. Every set of apex seals I take out of rx8 engines is worn in the center and tall on the edges.

3) the chrome layer on the rx8 rotor housings is significantly thinner than what was on some of the older housings, since there is less chrome thickness it tends to groove and flake more easily, so the rotor housings are in rougher shape at lower mileages. Most of the engines I tear down with more than 100k miles are not in good enough condition to reuse and still build a nice engine.

Even if apex seal wear and weak compression do not cause the engine to become difficult to hot restart and idle without stalling, the coolant seals don't seem to last much beyond 100-125k miles as far as I can tell.

Bottom line, if you own one of these cars, here is what I'd plan on:

-ignition coils and plugs every 50k miles

-cat converter 100-125k miles

-engine rebuild/replacement 80-100k miles

And if you make it past those values on the original parts then you've done well.

 

My first 8 made it to 82,210 miles but I believe a cat issue caused premature wear to the seals which made my engine start to lose compression over time. It wasn't as if my engine completely lost compression, it was just losing compression quickly within 1,000 miles. (Had 2 compression tests) and my warranty had a week left so Mazda took care of it for me thankfully.

My '07 already has 49,000 miles now and runs strong. I'm changing my ignition parts soon, just waiting for the shipment to arrive, hoping to beat my record with my first 8.

 

My '05 8 just ticked over 109,000 miles this week. I'm the original owner. Everything in the drive train (including the clutch) is original. Only mod is BHR ignition kit installed at 97,000 miles after failure of front rotor leading coil and a K&N drop in filter. I have pre-mixed since about 50,000 miles. Other than that ignition coil failure, everything else has been routine spark plug & fluid changes, brakes & tires. Probably helps that I baby it and drive a lot of highway miles.

 

A good quality Premix IMHO is the key to a happy engine.

My FC has no OMP, it is taken off and the injectors removed, I premix 8 oz. per 10 gallons for street driving and 10 ounces per 10 gallons for AX / Track / Spirited driving.

My RX8 only had 16K miles on it when I bought it, I immediately purchased premix and started. I think this engine is new enough that the first 16K minus premix will not be an issue. I am running 6 oz. per 10 gallons in it 8 oz per 10 gallons if I am Autocrossing it.

 

According to a tech at Atkins, he estimated the "average" Renesis (Series I) to be good for 160,000 miles, assuming the oil was kept clean and topped off, coolant was changed within reasonable intervals, and no forced induction or major aftermarket mods were done to it.

He said the failures at under 100k are due primarily to neglect and major mods.

I'm not saying he's correct or not, but they see quite a bit of action.

 

I have a series 1 05 rx8 just hit 90,000 miles the other day engine is still strong.

mod list:
SOHN adapter ( ams oil sabre premix)
header
mid pipe(rp supercat)
BHR ignition
exhaust
ap pulley
fan controller
AEM intake

I think/hope she will continue to run good for at least another 20,000-40,000 miles hopefully more!

then im swapping in a 13brew.

 

I've got 88K on my '06 and it still runs great, original engine. I've had no major issues, just routine maintenance or minor easy fixes like flushing and replacing transmission fluid. I would like to upgrade to a BHR ignition system though.

 

After 7 years of owning one, things replaced:

1. 3 sets of spark plugs (all covered by dealership)
2. Midpipe (Stock cat is POS replaced with AP Midpipe)
3. Ignition Coils (replaced with BHR Ignition System) well worth it

Its pretty much the most reliable car I've ever owned and I was worried it will blow up since day 1, got bored with it though then I sold it. Researched on other Japan made sports cars, turns out other sports cars have more problems than the 8.