Skimmed the thread, but...

Seems like this motor was simply over-revved at under-temp.
All of the damage is "crash" wear, not long-term wear.

 

I don't know where anyone has said that the "engine has failed" because of oil viscosity, again the subject matter in this thread is about "Bearings" which just happen to be lubricated by engine oil....the same design, and tolerances, materials and everything else that is over decades old and used in rotaries as far back as 1969.

This wear has not been seen on low mileage engines until the RENESIS, and on more than one continent using different brands of engine oils so I would call it very consistent.

You really only have to look at the changes made between Series to see the issue that concerned Mazda and most (all) in the 8 from the engines engineering point have been oil/lubrication related. Everything else has remained as it was from a replacement parts point.

The "User Related" warning applies in everything Humans do in life...

I have to agree with OD about oil viscosity......particularly rotaries....and fresh is best!

 

If you were referring to my post you overfocused on my faulty name of the problem, engine fail. Ok it didn't fail, but you are still kinda blaming everything in the first post on oil viscosity. I'd say the oil is a possible cause, but the user has more hands into this including oil quality due to user input, as the user can both have been overreving it when cold like MM mentioned, but also he could have been not changing oil for 12k miles like mentioned, would the viscosity matter much at that point?

I'm just trying to say I'd be more likely to take conclusions if I knew the user did everything right.

 

Bingo.

 

Umm, no Bingo..

The UK Owner appears to be an enthusiast and says is rebuilding an RX-3..as far a High revving on a cold motor...I personally don't see the evidence.

What I do see is the same type/look of Stationary Bearing Wear in just about every Pic of a naked RENESIS posted on this and other forums.

"Crash Wear"..??

BTW. The User said he Used 5W30 and Regularly Topped Off Engine Oil and his car never overheated or gave problems apart from Coils/plugs?

 

Hmmm. So, more pressure with a good 0W-40 = more flow right? More flow with a oil with good viscosity means better lubrication and cooling.

 

yall want to make it even more techical and start talking about some more concerns---film strengh and particle suspension properties?
OD

 

I think there are owners out there that rev the **** out of their engines when cold. but the point here is that, when everything is the same (as least the parts in questions are), We ONLY see bearing wear like "this" on Renesis even with little miles.

when 99.99% of the stuff is the same except for, well, in this case, "thinner" 5w20/30 oil. Shouldn't that tell anybody "something" ?

Bingo what? Bingo yes 5w20 is total garbage, and 5w30 is close enough to be garbage? for this engine at least.

 

YES!!! But I'm just hear to learn so don't expect me to have any input on strength or particle suspension,

 

Yes, 0W-40 or 0W-50 FTW!!!

 

Well put, the RENESIS is not the first rotary that may have had the revs shat out of it when cold.

I think I will shut up from now on...it does not matter what is said, and how much you say it, some can't see the wood for the trees mate.

How many more times should I show the reference and say that these engine parts are all the bloody same, for the past 20-40 years, well sorry 99.99%.

...it is the.....OIL....OIL.....OIL....OIL

 

But they haven't seen the same oil. And I'm not talking just about viscosity.

The other change was when API service classification changed from Sl to Sm, and that just happened to occur not long after the Renesis hit the market -- fall 2004.

With SL, anti-wear addiditve ZDDP was decreased significantly. Since then there have been many reports of accelerated engine wear in various engines, not just the Renesis.

 

We have a winner!

15W-40 or 20W-50 with lots of ZDDP for the win.

 

Not quite. Higher viscosity does equate to higher pressure, but not higher flow. The flow rate is established by the positive displacement oil pump which means the flow rate is fixed.

But, the higher viscosity will resuly in a thicker film, which will reduce the possibility of metal-on-metal contact. Which is to say, better lubrication.

At least, that's what the basic theory has to say. Obviously, there are other variables that affect the situation as well, such as the mentioned reduction in the ZDDP additive, which I find somewhat depressing. Why would that happen?

I guess I'll keep on using Royal Purple, which has their own anti-wear additives.

 

This is what Castrol has to say about their 20W-50 (my emphasis added):

 

Zinc and Phosphorus removal....to preserve your CAT and Environment for the EPA and tree huggers...

 

The SL / SM thing is very interesting. Surfing around you can find many pages saying things about increased wear as a result of the lower levels of ZDDP. On THIS link i found the below text.

ZDDP additive provides a high level of anti-wear protection, but its phosphorus content is harmful to catalytic converters and other emission equipment fitted to many modern vehicles. It has therefore been reduced in the latest specification oils, designed for engines using the latest surface hardening technology and meeting the latest emission requirements for modern vehicles. These requirements also necessitate the use of other new emission equipment friendly additives not designed for use in veteran, vintage and classic car engines.

It looks like the dam CAT is to blame again. Our 8's run rich ( waste fuel lower power) so the CAT can last longer. It now may well be ours, and other engines will not last as long in order to prolong the CAT. THIS article recommends using diesel oils, something I have also seen posted here.

 

Well put. Thanks.

 

Hmmmmmmmm. ****, more info to contemplate.

 

This is the most important part of that paragraph. While ZDDP has been reduced there have been other additives which provide barrier protection that are being used instead. ZDDP is old technology and not as necessary in modern engines as it was with flat tappet cam motors or older vehicles.

 

But as ASH pointed out there still is some old tech being used in the Renesis.

 

^Me too.
Run all the "big rig" oil you want.
Somehow the numbers or teardowns all have the same where and tear. So my next question is; Is this the norm for the SE3P? a rebuild every 60k miles?

 

Of course they're not using the same oil. Yes I think I know that

The problem here is that, "while" they significantly lowered the ZDDP count at the SM grade (its gay I know), but they did add some other stuff to it to try to "balance" it a bit. JUST a bit tho.

Cuz there are things in science, no matter how hard you try, cant be replaced.

Anyway, Mazda knew wtf they did to the oil, but they still "recommended" the pathetic 5w20 ... which has close to no film strength in the first place ... well, thats their choice.

This "5w20" combined with "sucky" OMP rate + those 2 stupid nozzle point at corners ... came back to bite them, HARD.

I have oils from all companies, today I just got 5 quarts of Mobil1 15w50, autozone got this 5 quart + mobil1 filter for 29.99, I got 20 bux rewards so the whole thing cost me like 13 bux so WHY NOT?

yeah yeah its SM grade, yeah I know I know they get weak after 1000 something miles but I change my oil every so often so it doesnt really matter, NOT TO MENTION. Fresh oil always beats old oil. why not ?

I still have some RP 20w50. For the record Royal Purple's 20w50 is actually SJ grade. Which I like even more than SL.

Jesus, you know how many times I've shown people those quotes? at least 5 times I gotta say. but hey, people still "dont see" them for some reason. like that moron rxrocks (See the Synthetic Thread for details)

We got lots of tree hungers, u know

What they dont see is when people's engine breaks down, they WILL replace it with another one, which increases pollution cuz it takes a lot of resources to make them.

 

yep,

i got it wrong. it is a visual clue that works off the same sensor that the manual gauge works off???? and yep that damn ecu controls all of it..

beers

 

Still not exactly right, because more viscosity will pop the pressure relief bypass off at a lower level of flow than a lower viscosity oil.
And even though it's a positive displacement pump, there is always some level of cavitation, so a thicker oil will result in slightly less oil pumped per revolution.
Less flow at the higher RPM's the Renny can take = more heat generated at the bearings (yes, it's only 2krpm more than an earlier motor, but the heat generated is a squared function of surface speed, so it's quite significant) = lower oil viscosity at the bearings due to heat lvel = old oil may well be breaking down in the bearings due to heat + pressure = bearing wear.

Like I said before, it's not cut and shut evidence either way.