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Possible New Renesis Engine Failure Theory?

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Old 01-25-2011, 11:38 AM
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I think its funny how we obsess over how long the renesis will last. Truth is, why worry about when the engine is going to blow up when you can just enjoy it. So what if the engine goes at 100K, thats when you rebuild it. Just take care of the car and enjoy driving it!
Old 01-25-2011, 11:39 AM
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Excellent write up 9k.
Old 01-25-2011, 11:44 AM
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Just one correction:

Originally Posted by 9krpmrx8
, We have seen bearing wear. I attribute that to insufficient 5W-20 oil in high load/high temp "extreme" situations and possibly due to low oil pressure. Running fully synthetic (if you have the SOHN) 40 weight or higher is a good idea and changing your oil regularly is a must due to the amount that remains in the engine and coolers. The Mazmart oil pressure mod is a no brainer.
Actually nothing wrong with 20weight oils if you have the oil pressure mod. As we stated earlier so many times, the S1 Renesis does not exist the factory reference oil pressures with the original regulators, even if you use 40w oil. So the pressure mod is a must have! After that a 30w synth oil is safe and good for internal cooling.
Old 01-25-2011, 11:48 AM
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Come to think of it the only data that would be of any value from the Star mazda engines would be on the side/corner seals.
If I am not mistaken--they are allowed to run ceramic seals, they have motec engine management with a good fuel pressure regulator and they do NOT ask anything from the engine until the oil is at least 165F?
Interestingly they have been having some trouble with oxgenated gas and their fuel delivery systems!
Old 01-25-2011, 11:49 AM
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Originally Posted by 9krpmrx8
Personally, I believe a few things contribute to the premature failure of the Renesis motor. I think you can look at the changes to the Series II and get a good idea of what the problem areas are with the Series I.

I think a malfunctioning OMP system will affect engine life eventually. Whether the affect is from the lack of cooling from the oil injectors or from a lack of lubrication is debatable but likely both are important. IMO, Injecting dirty engine oil is not ideal, Mazda only did this because the normal owner is not going to monitor and refill an oil reservoir. Premixing also helps but again, the average owner is not going to mess with premixing their fuel. I believe premixing and running the SOHN are necessary if you want your engine to live a long healthy life. We have seen bearing wear. I attribute that to insufficient 5W-20 oil in high load/high temp "extreme" situations and possibly due to low oil pressure. Running fully synthetic (if you have the SOHN) 40 weight or higher is a good idea and changing your oil regularly is a must due to the amount that remains in the engine and coolers. The Mazmart oil pressure mod is a no brainer.

Cooling is always a concern. Coolant temps and oil temps should be monitored and if you are seeing excessive temps then they should be addressed. There are several options to address these issues like proper ducting, freeing up area behind the fans, secondary radiators, Mazmart water pump, Mazmart Thermostat, better radiators (griffin, Ron Davis, etc.) better oil coolers, or simplified oil lines like the Racing Beat lines, and better coolers or a large single oil cooler.

Filtration is also important, and personally I don’t think there is any real benefit to running a hi flow filter on a street driven vehicle. The minuscule HP gains are far outweighed by the damage sand and other types of dirt can do to your engine. All I have to do is look at the built up dirt in the tray under my intake box to see what could possibly make it into my engine. I’ll stick with an OEM type WIX filter on this motor.

Habits are important too, if you are the type who just gets in your car in the morning and takes off, driving hard when the engine and oil are cold, then you are likely doing damage to your engine. The engine needs to be warmed up before revving hard and a stock 8 takes some time to get fully warmed up. I am in South Texas and even here when the factory temp gauge reads normal, the oil is still too cold to start redlining or putting a high load on the engine. However, to avoid moisture in the oil, and to help minimize carbon build up the RX8 needs to warmed up and driven hard from time to time.

Of course, if you only plan on owning the RX8 for a year or two and could care less if it makes it to 100-150,000 miles then just drive the damn thing and don’t worry about all this
I'm gonna shuffle in and snip this for my new owner's thread I think....
Old 01-25-2011, 11:52 AM
  #356  
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Originally Posted by tigersilhouette
I think its funny how we obsess over how long the renesis will last. Truth is, why worry about when the engine is going to blow up when you can just enjoy it. So what if the engine goes at 100K, thats when you rebuild it. Just take care of the car and enjoy driving it!
I obsess in everything I do

But when you pay 25-30k for a car you don't want or expect to be paying for or dealing with engine rebuilds. And if your engine goes at 100k it's not easy for everyone to just come up with $3,000.00 for an engine replacement when some are still making payments. Not to mention that dealers are getting tougher and tougher on honoring the warranty. We had a guy who only owned his 8 a year when the engine went and they denied the replacement under warranty because of the lack of oil change receipts because he did them on his own. He just traded it in to another dealer (engine was still running but had low compression) and got a Maxima.

So if you are the type (like me) to keep cars as long as possible then making sure the renny lasts is important.
Old 01-25-2011, 11:56 AM
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Originally Posted by shadycrew31
Excellent write up 9k.
Thanks

Originally Posted by ayrton012
Just one correction:



Actually nothing wrong with 20weight oils if you have the oil pressure mod. As we stated earlier so many times, the S1 Renesis does not exist the factory reference oil pressures with the original regulators, even if you use 40w oil. So the pressure mod is a must have! After that a 30w synth oil is safe and good for internal cooling.
I guess so, but for me. it's a "why bother?" when you could run a 5W-40, 0W-40, or higher?. I ran GC 0W-30 and was not happy with the break down in only 1500 miles so I have used a 40 every since with good test results. But if you do use a 20W, I would suggest testing it to make sure it is still maintaining viscosity after a hard 3,000 mile oil change interval.

Originally Posted by RIWWP
I'm gonna shuffle in and snip this for my new owner's thread I think....
Cool
Old 01-25-2011, 12:01 PM
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Originally Posted by 9krpmrx8
I obsess in everything I do

But when you pay 25-30k for a car you don't want or expect to be paying for or dealing with engine rebuilds. And if your engine goes at 100k it's not easy for everyone to just come up with $3,000.00 for an engine replacement when some are still making payments. Not to mention that dealers are getting tougher and tougher on honoring the warranty. We had a guy who only owned his 8 a year when the engine went and they denied the replacement under warranty because of the lack of oil change receipts because he did them on his own. He just traded it in to another dealer (engine was still running but had low compression) and got a Maxima.

So if you are the type (like me) to keep cars as long as possible then making sure the renny lasts is important.
Thats a good point. I owned a bunch of turbocharged SAABs before the RX-8 and with those cars you'd have to replace this and that constantly and they almost always left me on the side of the road, despite meticulous maintenance. That was a serious disappointment for me. With the RX-8, other than the threat of a new engine at 100K, its been a very reliable daily driver. I think I trust this car alot more than my past ones I do care a lot about my 8, it makes me smile everytime I hit redline!

-Lawrence
Old 01-25-2011, 01:34 PM
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Originally Posted by 9krpmrx8
Thanks



I guess so, but for me. it's a "why bother?" when you could run a 5W-40, 0W-40, or higher?. I ran GC 0W-30 and was not happy with the break down in only 1500 miles so I have used a 40 every since with good test results. But if you do use a 20W, I would suggest testing it to make sure it is still maintaining viscosity after a hard 3,000 mile oil change interval.



Cool
I did notice in the UOA thread that they lose viscosity pretty bad. Your 30w ends up being 20 after 1,000 miles. So if 30 was good, that means 40 will get there soon enough.
Old 01-25-2011, 11:18 PM
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Originally Posted by Beodude
I did notice in the UOA thread that they lose viscosity pretty bad. Your 30w ends up being 20 after 1,000 miles. So if 30 was good, that means 40 will get there soon enough.
It's not that simple, the numbers on the bottle don't mean a whole lot for the most part. They give you an idea but that is about it. A good 5W-20 can outperform a good 10W-40, it just depends. I have tested quite a few oils over the years and they all seem to vary by brand and weight. A Castrol GTX non synthetic 10W-30 may test better than or equal too an Amsoil 10W-30 or some other true synthetic. There are a lot of factors to consider when looking at UOA's. The oil, driving conditions, driving habits, engine, etc.

What does well in one may not do so hot in another. The GC (German Castrol) 0W-30 is a special European formula pure synthetic and is loved by many in the euro world and tests great. It just didn't do so great after 1500 miles in my engine right after the break in period. It wasn't bad but it wasn't where a full synthetic should have been either. That doesn't mean the oil is bad.

Just pick an oil and test if a couple of times. It's cheap to do and you will have a good idea if your oil is doing okay for your oil change habits and driving style or not.

But basically just pick and oil and change it as often as you can. I don't want to start an oil debate, there are many great oil formulations out there.
Old 01-26-2011, 02:21 AM
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Originally Posted by Beodude
I did notice in the UOA thread that they lose viscosity pretty bad. Your 30w ends up being 20 after 1,000 miles. So if 30 was good, that means 40 will get there soon enough.
True, but if anybody has (I know you have) oil pressure gauge, you can check the pressure drop, if the oil viscosity decreases.
Old 01-26-2011, 08:06 AM
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its not the actual viscosity that decreases as much as it is the film strenght of the oil that decreases? The film strenght is what you need to be wary off.
Search nobb!!---Sorry I couldnt help myself there
OD

Last edited by olddragger; 01-26-2011 at 08:09 AM.
Old 01-26-2011, 10:05 AM
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I wasn't trying to start the oil thing. I was just commenting. LoL

OD, I'm pretty sure I'm still considered a newb... Haha! I've been on here for about 5 years or so. My old name got banned for Russian spam or something.
Old 01-26-2011, 10:18 AM
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Originally Posted by 9krpmrx8
Thanks



I guess so, but for me. it's a "why bother?" when you could run a 5W-40, 0W-40, or higher?. I ran GC 0W-30 and was not happy with the break down in only 1500 miles so I have used a 40 every since with good test results. But if you do use a 20W, I would suggest testing it to make sure it is still maintaining viscosity after a hard 3,000 mile oil change interval.



Cool
hmm that 20w50 in my engine looks goooood.

One thing I notice tho is that, the only brand that holds up pressure "well" after maybe 1-1.5 K miles is Redline.

All other brands I tried, including Royal Purple. drops pressure after said miles. Some more, some less. depends on the brand (tried RP, M1, Quakers State, Castrol, with varies weight)

I never test the redline oil so dunno if thats valid, but I trust my oil pressure gauge, if I see idle pressure drops, I change them.

and of course im gonna replace the regulator when it gets warmer
Old 01-26-2011, 10:58 AM
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nom nom more oil debates!
Old 01-26-2011, 11:07 AM
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I was thinking too that you guys that track could also install a third oil cooler but using a oil filter adapter plate, that way it would be easy to close off during the winter or when not tracking or driving in extreme temps. The convenience of a secondary radiator (via heater hose) or tertiary oil cooler using an oil filter adapter plate is that it makes no permanent changes to the vehicle. This way you don't have to worry about warranty issues.
Old 01-26-2011, 01:10 PM
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Film strength hardly depends on viscosity. But pressure depends on viscosity if you have a fixed volume capacity.

Originally Posted by nycgps
hmm that 20w50 in my engine looks goooood.

One thing I notice tho is that, the only brand that holds up pressure "well" after maybe 1-1.5 K miles is Redline.

All other brands I tried, including Royal Purple. drops pressure after said miles. Some more, some less. depends on the brand (tried RP, M1, Quakers State, Castrol, with varies weight)

I never test the redline oil so dunno if thats valid, but I trust my oil pressure gauge, if I see idle pressure drops, I change them.

and of course im gonna replace the regulator when it gets warmer
gh

I'm always well above the factory recommended oil pressure with the 0w-30, changing at 3000M. Maybe with 20w-50 i would be at max pressure just above idle. But who wants that?
Old 01-27-2011, 04:44 AM
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Old 01-27-2011, 08:27 AM
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lol! Me too.
Old 01-27-2011, 09:55 AM
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Every good thread has to come to an end i guess Hopefully some people have learned a thing or too, I know I have.
Old 01-27-2011, 10:41 AM
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I think everyone has!
Old 01-28-2011, 03:20 AM
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I'm always well above the factory recommended oil pressure with the 0w-30, changing at 3000M. Maybe with 20w-50 i would be at max pressure just above idle. But who wants that?
My pressure gauge verified these.

But I forgot to mention (sorry), that this is true if you did the regulators mod, and I have a less flow resistance single oil cooler system.

With the factory pressure regulators, that quoted statement is not true.
Old 01-28-2011, 01:36 PM
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Originally Posted by 9krpmrx8
Every good thread has to come to an end i guess Hopefully some people have learned a thing or too, I know I have.
I definitely enjoyed it a lot. Learned a ton.
Old 01-28-2011, 08:33 PM
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they are also using teflon lines with really good results, but either or just pick one. The stainless lines would be much harder to run though.
Old 02-09-2011, 02:40 PM
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Originally Posted by 9krpmrx8
I obsess in everything I do

But when you pay 25-30k for a car you don't want or expect to be paying for or dealing with engine rebuilds. And if your engine goes at 100k it's not easy for everyone to just come up with $3,000.00 for an engine replacement when some are still making payments. Not to mention that dealers are getting tougher and tougher on honoring the warranty. We had a guy who only owned his 8 a year when the engine went and they denied the replacement under warranty because of the lack of oil change receipts because he did them on his own. He just traded it in to another dealer (engine was still running but had low compression) and got a Maxima.

So if you are the type (like me) to keep cars as long as possible then making sure the renny lasts is important.
i can vouch for that.... his car will be one of those that will last till the messiah returns


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