If anyone has more questions, feel free to enquire.

At this point, I would like to ask if anyone has any recommendations to try a different maintenance routine, please let me know...

The fact of the matter is... with my driving habits/conditions, the routine I have done now has lead me to this point at 98,000 km. This is a fact.

 

Yeah, in Japan, they use OEM Mazda Synthetic Oil on RX-8.....

http://www.mazda-auto.hu/userfiles/r...hetic_olaj.jpg

Or use RE-Amemiya, HKS, FEED, engine oil, if you don't want to use conventional oil.....

http://www.re-amemiya.co.jp/commodit...a1534&scd=8529

http://www.fujitaengineeringusa.com/other.html

(The HKS Rotary Engine Oil only for RX-7 though)
http://www.hks-power.co.jp/products/...oil/index.html

 

One thing for thought here. When checking compression on a rotary engine you need to use a battery charger on "start" mode that will keep your rpm consistent when cranking. I cant tell you how many mechanics at dealerships dont know this basic fundmental. We do about 5 compression checks a year and if just cranking on the battery alone we lose about 1.5 - 2 kpa of compression. Regarding your oil, the weight of the oil has nothing to do with lack of compression as it doesnt affect the apex seals. If your compression loss is because of main bearing issues your engine would be seized by now.

Oil related compression issues would only be caused by over oiling the apex seals with premixing, added oil injection, heavier oil or synthetic oil that wont completely burn off and gums up the seals and springs so they wont move freely.

One of the big reasons for compression failure that no one wnats to admit to is that the RX8 apex seals are very small compared to other 13B steel seals. Thats why when we use RX8 rotors for racing they are machined to accept the much bigger and stronger 3mm seals of the last generation engines. To get 60,000 miles from a 2mm seal that has been driven hard is quite a good accomplishment. To put this in perspective for everyone the life span of a 3mm carbon apex seal is about 24 hours of high rpm use. The 3mm ceramic seals that cost 8X that of a carbon seal is usually longer than the rotor housing lol.

 

And yet, we have Elf out there with almost 250,000 miles on the original motor. Go figure...

I'm guessing variable manufacturing assembly tolerances, or OMP settings/functionality, but who knows.

 

What were your driving habbits like? Were they short city trips mostly or longer highway trips? Was the car parked outside? Also I assume you didn't redline until the car was warmed up?

Your OMP usage seems a bit low... I average 1qt per 1000 miles. Anyway, I got my car at 47k miles (75k km) and it passed a compression check then. I'm at around 82k km now and it seems the same... I'll probably dyno it soon. As far as I can tell the previous owner just had routine oil changes every 4k miles and probably topped up inbetween. Not sure about the plugs, but I'll be doing the BHR upgrade soon.

 

It seems that Footman was doing a lot of relatively high-rpm driving, lots of redlines, etc. And, whereas this is good to scavenge carbon, might this be a bit of well-intended overkill and relatively bad for overall seal wear?

All other things being equal, more revolutions = more wear, right?

 

Footman,

I'm sorry to hear you'll need an engine, but on the plus side, you're getting a new engine!

In seriousness, you had to expect to get a new engine soon. These little engines provide an enormous amount of power for their size.

The only thing I've always been skeptical about was the engine oil. I knew there wouldn't be much of a difference between engine history. The Renesis just has no side ports on the same old block. So how in God's name does the engine oil become so light??

It's all because of "fuel economy". Less oil to move around, the better fuel economy.

If I had an RX-8, I would still be using 10w30. The standard oil weight for rotaries for the longest of time. And this is conventional oil. Despite what you might think, synthetic never burns properly. So for piece of mind, I would use conventional oil.
Also, I would still use the OEM OMP for the oil distribution. I know it's a compromise, but unless you're using the car to race in Grand Prix's, the OEM OMP does more than ample job getting oil into the engine.

Cheer up Footman.. you're getting a new engine.
Give me suggestion a try. 10w30 is more than enough for rotaries for daily use. Too bad we weren't in warmer climates, then some of us would be running 20w50 or something crazy heavy like that.
But for Canada, 10w30 is more than enough.

Can't wait for the new season to start!

 

Sorry for your loss and thank you for sharing the info. Pretty disheartening given your care of the car.

It is pretty sad that most of us have to hope for the engine to fail before the warranty period runs out...

 

My advice is not to trust a timing light. Just because a coil fires it doesn't that its output is right.

01Racing added something interesting but a higher oil weight and premix will just lengthen your engine's life (even if for different reasons and areas of concern). To gum up the seals you'd need to be a completely reckless and drunk monkey.
There's no real replacement for the lack of a central oil nozzle, premix alleviates this issue though. Just take 2 apex seals, one that only saw regular injection and one that saw consistent premix and put them on a flat surface to see for yourself.
Books could be written about 2 and 3mm seals and their pros and cons. In a stock renesis you'd still be having side seal (and side seal springs) problems way before seeing excessive wear at the rotor's apexes.

I would raise the oil system's pressure. It doesn't directly affect engine life compression wise but it's a great addition for peace of mind. The s1 13b-msp is the only engine in the 13b family that runs with such a low pressure

 

When I was a Mazda dealer I went to QA at Mazda Canada and watched the only person in Canada who was trained at the factory in Japan on building/rebuilding rotary engine tear a 13B renesis down after it was condemned by a dealership technician. The heavier synthetic oil that was used most definately caused the apex seal to gum up and stick with no question what so ever. The engine had continuous flooding issues and after a compression check was condemned. The person at MCI showed how easily this issue was resolved and truly the egine was fine and should not have been replaced. These discussions have been going around and around the forums for years and will continue to do so, with countless individuals trying to out engineeer the factory. Using heavier oil in our cold climate will result in more flooding issues as the heavier oils make it harder for the car to crank quickly when very cold which is one of the mail reasons for the lighter weight oil in temperatures under 5degrees C.

 

How many years ago did the synthetic gum the engine up? Because modern synthetics burn cleaner than any mineral, the only problem being some (like mobil 1) not mixing well with fuel.
5w30, 5w40 and 10w40 oils have similar cold cST, the cold start issue is, in fact, a non issue.
It's not out-engineering the factory, it's just being smart. America the only place where mazda states to use semi synth 5w20 oils only. In the rest of the world they assume that the owner is smart enough to determine what weight and type of oil to use. Our service manuals (europe) give you a nice temperature vs oil viscosity chart to follow.
In japan mazda sells a synthetic dexelia just for the wankel. Real race teams only use synthetics.
Mazda doesn't explicitly say to use synthetic oils because there are some that are known to be dangerous. It's just legal, not mechanical stuff.
Rotarygod quoted somebody from mazda years ago to show that, search for it!

 

Seriously, does this picture http://www.mazda-auto.hu/userfiles/r...hetic_olaj.jpg not say it all???

It is a GROUP IV based synthetic oil. http://www.mazda.co.jp/service/parts...e_renesis.html
If you do the language translation, it says that it's formulated from mostly PAO ester, which is a group IV base. A lot of "synthetics" are still group III with modifiers to make them meet the requirements to be called "Synthetic"

Also, want to re-iterate Mazda Japan says okay to use 0W30 or 10W30 conventional in their climate. I think Hokkaido, Japan is as cold as Toronto, Canada in winter.

I am now on the hunt for GROUP IV based synthetic oils 0W30 as I don't think we can import the Synthe-Renesis oil in Canada.

My other option is to look at conventional 5W30 oils.

Neo, looking at the temperature charts, I can't risk using 10W30 in case there is a day where it does get really cold here, remember. The car's requirement is that it must be daily driven in all temperatures, I need something more ,like 5W30 at the bare minimum.

 

I'm not going back to the whole argument of burning because the whole point of a Mobil 1 or Redline synthetic oil is that it takes a much higher temp to burn it off or get it to break down as that is the whole point of the oil. If Mazda has its own rotary synthetic oil than thats great and amazing, I would bet its not off the shelf easily accessed oil. Footman the only advise I have is to remember that the heavier the oil that harder cranking it will be and slower the initial oil flow will be to critical bearings etc in colder weather. Do you know if you will get a new or rebuilt engine? When I was with Mazda it was 50/50 which engine was delivered.

 

Neo, our new 2011 and 2012 Toyota's all come with 0W20 synthetic oil from the factory. The manufacturers change bearing design to allow for the lighter weight oils. The lighter weight oils give you more free horsepower (old racing trick from way back) better fuel ecomony and lower emissions, thats why we have 5W20 and 0W20 in North America.

 

I am getting a remanufactured from USA confirmed. Unfortunately, not getting a new one from Japan. They are also reusing my OMP, UIM, coils/plugs, etc... all I am getting is the block.

Not sure if you have had any experiences with those back in your Mazda days at Scarboro?

Avante is doing the work, and they told me they did a few and none have ever came back with problems.... crossed my fingers.

Some good dicussion here on oils: http://www.upmpg.com/tech_articles/motoroil_viscosity/

Also good review on 18 oils here with PICTURES: http://www.animegame.com/cars/Oil%20Tests.pdf

 

I understand as the times progress, and the materials being used get better regarding tolerances, thinning out the oil to get better fuel economy is not a good way of doing it.
It's fine if you're racing, but not when you're dealing with daily driven vehicles that go through a variety of temperature changes...

I'm still a little against using synthetic oil. All engines burn oil regardless of make. There are people who state they don't burn an ounce of oil. But I seriously doubt it.
My Miata goes through oil. And it's a conventional 4 piston engine. After about 4k km's, I've got to put almost a full litre of oil back into the car.
Which is fine since I've realized this when I had my Mazda3 (2005). It too burned oil. Usually about 1/2 a litre after about 5k km's.

If you think the luxury cars are any better, they're not. My old man's 2008 BMW 323i burns about a full litre of 0w20 every 8k or so. And since the "computer" states an oil change doesn't happen till about 13-15k, he's gotta spend the extra cash for the synthetic oil because it's the only oil specified for the vehicle.

Footman,

You're right, the 10w30 spec for winter driving, not recommended. As per my RX-7 manual, use 5w30 for cold/winter driving. I would still follow the old chart specified for these engines. They're design is not vastly different from the first type of rotary engines.

I worry about these engines using such thin oil. My Miata is set to 5w20. I'm not completely convinced of it. But so far, so good. Granted, it's only got 120k on the clock. I'm only using the conventional 5w20 specified by the factory. And since I know the engine is burning oil, I wouldn't bother using synthetic.

Hopefully these brand new engines with direct injection don't start to clog up due to their designs.

 

Been thinking about this angle....

The rotary engine injects oil to lubricate the seals which is designed to burn off. If this material is not being burned off, wouldn't it just keep piling more and more eventually clogging everything.. exhaust ports/intake ports etc... and since synthetic is designed to resist burning with a higher flashpoint is this why synthetics are not recommended?

BUT THEN AGAIN....
Synthetic oils provide better lubricating and resistance to viscosity change with extreme temperature variations making them better at lubricating and cooling the eccentric shaft and rotor bearings.

The RX8 uses ONE OIL to do both tasks... I think this is why inherently it's going to fail. The bearings/journals require something that is opposite of what the apex seals require. ULtimately, the sohn adapter allowing two different types of oil is the best in my opinion.


Now onto another thought... the burn temperature of synthetic oils.. correct me if I'm wrong, but the flashpoint rating of an oil is the temperature at which the oil will smoke/burn/combust correct? If so, what's the temperature inside the combustion chamber? Isn't it usually much higher than the flashpoint even of synthetic oils? Then if that's the case, wouldn't it mean synthetics will STILL BURN off and be okay?

 

Synthetics are not recommended because early amine based synths ate the big 'O' rings out of rotaries.

Since no one knows which components are in which synthetic, Mazda just went with the safe, cover-your-*** blanket prohibition.

My first 12A was replaced in 1977, due to first-gen Mobil1 dissolving the side seals.

 

Footman, did you check if there's any oil around your oil pan?
I'm asking this because the 8s that are around my area which have replaced their motors ALL have this symptoms and have to add oil between oil changes. Never get the chance to look into it, but leads me to suspect that their OMP or somewhere is leaking.

Yes, I know motor burns oil, but in my 7 years of ownership, I never have to add any oil between oil changes, no oil around my oil pan neither. And I do reline whenever I hit highway ramp and premix 4oz of idemitsu per tank.

 

^No, no leaks at all anywhere.

 

I think the failures have to do more with the stock OMP system being inadequate, than the type of oil you use. IMHO, the rotary is a fragile engine and the failure point seems to be roughly around 100,000 KM's following manufacturer maintenance guidelines.

I have an '04 and my engine was replaced at 153,000 KM's (just barely made it under extended warranty), and oil was changed every 5,000 KM's, redlined once a day. Mine started exhibiting signs of failure around 140,000 KM's (slight hard to start when warm, and slowly progress to no start when warm). Just recently, a local RX8 club member where I live had her engine replaced, and she has only 44,000 KM's on her '05.

I currently have a COBB AP with MM Tune (highly recommend), which increases the OMP volumes.

Looks like they charge a lot more out east. My compression test was only $84 + HST @ Wolfe Mazda, and they didn't have to do an engine decarb. I also didn't have to pay anything to get it replaced - they didn't charge me for labor, fluids, gaskets, etc. even though I was well over the 5 year, 100K warranty. Yet others have had to pay for labor + parts and fluids.

 

Always interesting to read these engine obituaries, thanks for all the details .... and of course my condolences Footman. I wouldn't jump to the conclusion of "I'm to blame" or even "the oil's to blame". When it's their time, I wager every rotary will fail... it's just their destiny. Not much has changed in the 40 yrs between rotaries I've owned. I had two engine replacements in m y RX-2, one in my RX-8. Go figure.

So having been through this procedure of engine replacement I can only tell you that ...with time ...it will get better. Your new engine hopefully will be strong, even if a reman. My RX-8 replacement was a brand new JDM engine with documented (really) excellent compression (you might get a compression test done at the end of the rebuild to satisfy yourself of the goodness of the reman). In fact, the engine definitely 'felt' more powerful than the original (butt dyno) as well.

As these things happen, and the cause is uncertain, these oil discussions always come up. The "review on 18 oils" was a real eye-opener! Just wow! As to the safety/benefits of synthetic vs dino oil, I've gravitated to the synthetic side, but only to one I've found that has rotary history, as described below from their web site. Formulation vary so much, and as their are no ingredients listed on oil cans, I figured the safest way was to use a synthetic specifically formulated for rotary needs. If you are so inclinded, this might be the solution to your desire to do the most for your engine that's possible to do, oil wise that is.

Surprisingly, during all this oil talk, no one has mention Idemitsu Rotary oil..... Myself, I use the 8 for 3 seasons only, and when I'm planning on racing, I use the 20-50w (not shown below), otherwise the 10-30w or sometimes I mix. Whether it truly does anything better, I do not know for sure, but I feel better for using it anyway, and if it helps prolong the life of the bearing or the seals, better still and well worth the cost (I buy a case of each at a time.)

Enjoy your new engine and may it live long and strong

 

Also premix...

 

Exactly lol, now you know why we run 20W50 synthetic racing oil in the engine and proper 2 stroke pre mix in the gas at a 100:1 ratio. Even in the race engine when the temps are cold outside we back the oil off to a 10W30 at the start of the season. You are right about the unburned oil think of the old Mobile 1 commercial with the oil in the frying pan. IT DOESNT BURN lol, that is what causes the apex seals to gum up and stick and lose compression. I am sure a chemical engineer could design a semi synthetic oil that would serve both purposes and it would cost big $$$$.

 

With all 6 chambers showing low compression, the culprit here is more likely side seals than apex seals.