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Mazda RX-8, Auto Repair, Engine, Oil, Car Warranties
#1 of 115 Mazda RX 8's Engine Failure Problem
Feb 18, 2007 (1:17 pm)
The following is my opinion from reading the discussions about RX 8 problems from other RX 8 forums on the Internet and you can form your own opinion :::::::::
The only thing wrong with Mazda RX 8's sold in the USA is that Mazda requires the use of very thin light weight 5W-20 oil that breaks down and cannot protect the rotary engine and catalytic converter from early failure, because the normally very hot running engine runs very, very hot especially in slow traffic and long drives in warm weather. Every city in the USA has slow traffic jams and warm weather.
Every where else in the World (except in the USA) Mazda requires in the RX 8 Owners Manual the use of 5W-30 oil to adequately protect the very same hot running rotary engine that is in RX 8's in the USA. The heavier oil protects the engine and oil seals from failure and prevents oil blow by from ruining the catalytic converter, for over 200,000+ miles, as documented in many forums on the web.
For example, printed on Castrol bottles of 5W-20 weight synthetic oil, says "use only in cars used for short trips" and another 5W-20 Castrol bottle of non synthetic oil says "use only if required by the car manufacture". Other wise, Castrol ,who sets the standard for excellent oil, does not recommend the use of 5W-20 oil unless directed to by the car manufacture or for short trips.
In addition, Castrol can be objective with out any conflicts of interest about which oil weight not to use to protect an engine, because it does not manufacture cars nor have any vested interests or concerns about meeting EPA miles per gallon requirements to avoid fines.
In the USA the RX 8 engines using the very light 5W-20 weight oil last maybe for around 30,000 miles before needing to be rebuilt a number of times before and after expiration of the warranty. This is probably why Mazda now only warrants the car for 3 years or 36,000 miles instead of the prior warranty of 5 years or 50,000 miles. This is also clearly documented in many RX 8 owner web sites.
However, in the USA Mazda requires the use of inadequate light weight 5W-20 oil in order for Mazda to meet EPA miles per gallon (MPG) gas consumption requirements. This light weight oil shortens the life of this normally very hot running rotary motor to around 30,000 miles, at the expense of the consumer who needs to keep spending lots of money and time to keep it running.
The owners must keep them running because no dealership wants to take the car in on trade or offer a fair amount on trade due to the now widely known problems Mazda has caused to happen to the RX 8
New buyers should consider not buying Mazda RX 8 cars until Mazda permits USA owners to also use non synthetic 5W-30 oil in their rotary engine, without loosing their warranty, as Mazda recommends throughout the rest of the World. Mazda could still put in the USA, RX 8 owners manual, recommendations to use 5W-20 oil to satisfy EPA , but not cancel the warranty of those who wisely choose to use non synthetic 5W-30 oil as recommended by Mazda, thorough out the rest of the World.
A class action law suit will straighten out Mazda and increase the life of our cars and make the car worth a proper amount when traded. RX 8 owners in the USA did not buy their RX 8 with full disclosure by the Mazda dealership that the car motor and catalytic would wear out much, much quicker than other cars, due to Mazda oil requirements in the USA nor how Mazda treats the USA RX 8 customer.
My Mazda dealership before purchase told me the RX 8 motor would last over 200,000+ miles because it was the nature of engines. With the first oil change though they also told me they would not put 5W-30 weight oil in my RX 8 because according to them it would damage the engine (which is a lie) and would void the warranty, according to Mazda USA. Well it is common knowledge now with the USA Mazda required use of 5W-20 oil the engine will not last 200,000 miles as advertised and more like it the motor will only last around 30,000 miles before needing to be rebuilt again and again etc.
Every RX 8 owner in the USA had better individually or join together to fight the Mazda lies about the weight of oil to use in their RX 8 or their motor's will have a very short life with no one to blame in the long run except for your own lack of sticking up for yourself and what you know is right.
#2 of 115 Re: Mazda RX 8's Engine Failure Problem [oldtimer2]
Feb 21, 2007 (3:18 am)
Nearly every car I've ever owned has at some point, caught one of those thin plastic grocery bags up under CAT. The bag begins to melt as it ultimately wraps itself around the hot metal.
Now when this happened recently to my RX-8 AT, I thought, no problem, cause that super hot CAT is going to burn that plastic bag to a cider in one day. Three weeks later, the plastic is still there, very very slowly turning a light brown color and smelling with that hot plastic smell.
I've driven the car on the highway, and revved the engine to 6000-7000 fairly regularly in city driving. That plastic grocery is not NOT burning away. It's not even turning black. The plastic grocery bag is simply evaporating under low heat over a period of many many weeks.
The way this little incident is playing out, I'd have to say, there does not appear to be very much heat difference at the CAT between my RX-8 any other car I've ever owned.
#3 of 115 Re: Mazda RX 8's Engine Failure Problem [trispec]
Feb 21, 2007 (5:40 am)
There are many diferent types of catalytic converters but the two basic types are those that do and dont have air pumps. the one on the RX 8's, in order to do a better job at cleaning up the eshaust gas, has an air pump which pumps air into a port in the eshaust system ahead of the cat which enables the cat to better burn off the bad sxhaust emisions.
I don't know what your reply has to do about being duped by USA Masada as to why RX 8 engines are failing, which I wrote about, but what you said was interesting ....and there you go with an explanation about RX 8 Cats, their fresh air pumps and air injection ports..........Later,......and good luck with your RX 8 and dealer when the engine fails because you are forced to use the to light 5W-20 weight oil....when throughout the rest of the world Masda Japan requires in the owners manual that 5W-30 oil must be used to protect the engine for a long life (without having to be rebuilt numerious time before and after the warranty expires) for the car to run for 200,000 miles, as promoted by Masda sales.
I wonder who Mazda or Ford buys their oil from, so I can look up the specs and compare it to the RX 8's actual operating temperatures and oil shear requirements of the engine. I expect the findings will suport Castrol's recomentations that light 5W-20 weight oil (as required by Mazda USA to meet warranty provisions) should not be used in cars that are ever driven long distances or more than, very short trips, to prevent over heating and breaking down the oil protection of the engine.
If you were thinking by mentioning that the plastic bag not melting off Catlytic Converter has any thing to do with the operating temperature of the engine it dosen't !!! In addition to many other factors effecting the operating temperature of metal parts in the rotary engine, remember that (1) the speed (friction)of moving parts in the rotary engine, and (2) the much lighter weight and much smaller exterior surface of the engine to "sink" heat from the rotary engine, compared to a standard piston engine...all causes the rotary engine to opperate at least 50% hoter than piston engines, which therefore might survive the light weight 5W-20 weight oil...where the rotary engine can not !!!
Feb 21, 2007 (7:23 am)
I've heard that Honda, Ford, and Mercedes Benz all recommend 5W-20 synthetic for their cars now.
#5 of 115 Re: 5W-20 [fedlawman]
Feb 21, 2007 (11:36 am)
As you may know Honda, Ford, and Mercedes Benz in addition to Mazda, all have problems meeting EPA's miles per gallon (MPG) requirements for their fleet of cars to reduce more $$$ of the huge (million $$$) fines that EPA charges.
In order to reduce (huge) MPG gas fines, they have been recommending like Mazda the use of the very light 5W-20 weight oil to cut down the resistance to movement of parts in the motor caused by the heaver oil adhering to and protecting from metal to metal friction.
To understand more about EPA-MPG gas requirements and huge fines look on the web under EPA Gas MPG Requirements and (huge)Fines.
In this connection though, I understand Mercedes Benz has changed their recommendation for oil back to a 30W base oil and Honda is also considering doing the same, if not already done so, to prevent further engine failure claims by their valued customer. I guess Mazda customers come last !!!
More importantly remember that Castrol, who is the standard for good oil protection, does not recommend the use of their own 5W-20 oil under the same circumstances. In addition Ford makes Motorcraft light weight 5W-20 oil because they also own 33% of Mazda and probably have bigger problems meeting EPA - MPG gas requirements without EPA charging huge fines for their fleet of cars. Again the EPA web site gives examples of huge (millions $$$) fines that charges and manufactures want to reduce.
#6 of 115 Re: Mazda RX 8's Engine Failure Problem [trispec]
Feb 21, 2007 (8:36 pm)
Hay, I just caught on to the point you were trying to make in your response to my post about the RX 8 engine failures, light weight 5W-20 oil and hot engines breaking down the light oil.
Sorry I had tunnel vision when I read your response. If my response to you was interesting OK, if not ignore it.
Now hopefully in reply to your response, I think you were making the point that, if your Catalytic was not melting the plastic bag wrapped around it, then the engine should not be very hot. Very, very interesting deduction Dr Watson.
I can only believe you as to what you have observed.
Years ago the Cats were so hot that they caught everything on fire including dry grass, floor mats inside cars, things in trunks and oil mats under cars in ones garage and burned down houses.....which was all not good. I also remember when I was a kid replacing mufflers and Cats at a Sears auto garage for extra spending money, and that one also had to be careful in taking off a Cat. I was told that any pounding or cutting on the Cat could make a spark that would cause the cat to blow up in my face.
I surmise that the car industry has done something to make the cats safer and cooler because the fire problems have stopped. But how cool and how the industry did it I can only deduct. I suspect that they double walled the outside of the Cat and may have routed some of fresh air into and between the outer double wall of the Cat to make the outside more cooler. I only guess, as an Engineer.
I do know though the inside of a Cat must burn glowing hot to burn off unwanted gas in the exhaust but how hot this will make the outside of a modern Cat I do not know. But I might be concerned, if it was to cool because this might mean that the cat is plugged up with blow by oil through heat failed engine seals into the Cat. I know the tips of my exhaust is so hot I can not touch them, but I have not tried to put my hand close to or touch the outside of the Cat after a drive.
Your observation was a good one to ponder. Seals in engines though are failing due to too much heat as is evident from failed engines and cats plugged up with oil as documented on RX 8 owner forums. And mazda is building a factory according to their announcements to rebuild failed motors, but they will probably be rebuilt the same as the failed ones and use the same required oil to only fail again and again.
Good luck with your RX 8. I have thought about having the Mazda dealer put in a larger oil cooler to keep the oil from breaking down on long drives in hot weather. A larger oil cooler should not violate my warranty, where in using 5W-30 oil, like the rest of the world uses, would in the USA.
Oh, how many miles do you have on your RX 8 and have you yet taken many long 4 to 8 hour drives in hot weather with out any adverse engine symptoms ??? I am afraid to take long drives in warm weather after talking with a few master service techs that used to work at Mazda dealerships. Maybe a larger oil cooler is in my future........Later and thanks for the reply.
#7 of 115 Re: Mazda RX 8's Engine Failure Problem [oldtimer2]
Feb 23, 2007 (3:34 am)
Yeh, the situation of the plastic bag being wrapped around my CAT just caused my brain to fart. No other thinking on my part, sorry.
Here in Boston, and around New England, where I take my family on day trips, I can't really say that heat has ever been a big issue. We do have a maybe a dozen days of 90 plus weather each summer. And my commute into Boston was an hour of stop and go each day, but I bought my 2005 RX-8 AT brand new with 5 miles on the odometer in September so that first year of ownership started out with cool and cold weather driving for about 10K miles.
We've taken three 2000 miles trips, all in the winter between Boston and the mountains of NC. We've taken a single trip to Maine in July, 300 miles.
Now if I've lived in Texas, where my brother's family practically lives in an outdoor pool all summer and where they had forty straight days of 100 plus heat, I might be worried as hell about owning an RX-8.
#8 of 115 Re: Mazda RX 8's Engine Failure Problem [oldtimer2]
Mar 13, 2007 (1:08 am)
I'm seriously thinking of purchasing a leftover '06 on a local dealers lot. Reading this, two things spring to mind:
1. If you used 5W30 the entire time up until you had to take the car in for whatever reason, would Mazda notice if you switched back to 5W20 immediately prior to bringing it in? Could switching oil grades cause additional problems?
2. How much gas mileage do you actually lose by using 5W30?
#9 of 115 Re: Mazda RX 8's Engine Failure Problem [rhester]
Mar 13, 2007 (6:19 am)
If you think Mazda could tell -used- oil is 5W30 rather than 5W20 you've been watching too much CSI. There is no way they could tell by looking at the oil (or even by having it analyzed - it gets changed too much in use). However, they may ask you for "dated proof of purchase" of the 5W20 that is allegedly in the engine. I don't think switching grades would cause any problems due to the switch.
I don't know about the RX-8, but I've seen claims of about 5-10% fuel economy difference between 5W30 and 10W30.
#10 of 115 Re: Mazda RX 8's Engine Failure Problem [pathstar1]
Mar 13, 2007 (7:51 pm)
Thanks for the reply, pathstar
In that case, why doesn't everyone just use 5W30 until the point where the car needs to be taken in? Shoot, perhaps if we all used 5W30 we wouldn't NEED to take it in
Anyway, it doesn't look like I'll be getting the RX-8 I was spying. The dealer wants over 30k for it. A 2006! Ok, it is a Shinka package but that still Blue Books for $28k. I digress...