zoom44

it does seem to be also humdity related- dryer area have more problems. is that due tot he "cooling" effect of the humdity or is it that the dryer areas are also dusty so the coolers are getting clogged up with dust etc?

zoom44

would a fan hinder airflow at speed? maybe it should auto rotate at speed.

beachdog

I brought up the dryness factor in post 138. I'm sure a lot of the factors all have mentioned are contributory. The Australian's have areas that are hot and dry like our southwest and even their MT's have a single oil cooler as I understand. What they don't have is a Mazda spec calling for 5w-20.

Gomez

From our owners manual.....for except Europe, read Australia.

Gomez

Now if you were to follow that info (and I'm not suggesting you do), Vegas cars would be running a 15W-50 oil.

zoom44

yeah beach i was respondingto your post actually. i meantione d the different aussie oil spec in post # 1Y*

zoom44

or 20w50 which is what soemoen else mentioned Steve back on post # whatever

rotarynews.com

On the FD, there is a way to linearize the temperature gauge so that is actually shows the correct temperature.

http://www.geocities.com/MotorCity/G...tempgauge.html
http://us.share.geocities.com/sdrx7_...structions.pdf

Anyone want to tackle a project like this for the RX-8?

Baller

Or 0w40 Mobil 1

RX8world

Hello,this is my first post.I am from Cyprus and temperature here reaches 40 degrees celsius.All 8's here come with one oil cooler and yet no problems detected.As for the fan working for 20 min after engine off.......i know from mazda here that in very hot days is expected to run for 10 minutes maximum.Why 20 ...i don't now.I don't drive my 8 in the hot sun but only it the evenings where temp falls to 30-33 cel.I've installed an extra engine heat gauge.Most of the time,when i drive evening in the city the temp is about 95-98 cel.......but if i am in traffic it stays at about 103 cel.
I don't know if i was somehow helpful but if i hear anything suspicious i will inform you guys.

2004 model,stock,10k miles,N flash,98 octane and sometimes 100 octane fuel

Oktobernv

Ok kids.....here is the "update" from Vegas as of Friday Aug 5th


I stopped by Magic Mazda today about 4pm to check on my 8.

Still waiting for her engine.....sigh....

Here are some notes from my visit.


#1 - Magic has changed out "about 20" engines so far

#2 - Magic got five new engines this week total

#3 - So far ZERO 2005's have had engine failure at Magic

#4 - Magic has NOT had a SINGLE 8 come in with a bad engine in the last week or so. IT has been MUCH cooler here in Vegas over the last 10 days. About 93-103 instead of 112-118. So there is a DEFINITE connection between outside temp and the engine failure problems. When it was REALLY hot here Magic was getting between "3 and 4 RX's a DAY with engine failure"

#5 - I asked about oil.....weight.....syn....ect......my service rep says he ABSOLUTELY DOES NOT recommend Syn oil. NO way, never. I asked about running 20-50 instead of the 5-20. He felt 20-50 was WAY too heavy. Still feels 5-20 is best overall bet.

#6 - I asked if Mazda Corp has nailed down the engine problem yet. No, nothing new to report.


So that's about it....

The basic plan seems to be......change the engine.....update to the "new" flash and see what happens.


Rob in Vegas

Baller

So everytime we get a heat wave here in Vegas we get a new engine, I can live with that.

clydejmuggs

Changing the temp gauge will be a bit more of a challange on this vehicle I'm afraid.

Oktobernv

yea a new engine every year would be great except for the 45 day waiting period.



Rob in Vegas

sharward

Thanks for the update, Rod. A lot of us are "hanging on your every word" so to speak.

Fascinating factoids... Particularly the "no 2005s so far." One can only wonder if it's age, amount of use, design change between model years, or number of summer seasons that may be factors. And the drop in temperature coinciding with the drop in engine failures -- looks like a duck, walks like a duck, sounds like a duck...

We'll include you in our prayers to the engine gods tonight, Rob. Hopefully you'll be rollin' in your 8 soon. And when you are, look on the bright side -- you'll have a brand spankin' new powerhouse under that hood, and the autopsy done on your failed engine will be most helpful in getting to the bottom of the issue for the rest of the RX-8 family I'm sure.

rotarygod

Oh well, he doesn't know everything apparently. At least not about rotaries.

Baller

No kidding......Synthetic, there is no substitute.

rxeightr

Rotarygod asked for some Scanalyzer data. These were all pulled from the unit, with the exception of outdoor temperature (91 deg F), which came from the RX-8 display.

The CAN does not appear to measure oil temperature --

Fully warmed up & moving ~ 35-45 mph:
Air Intake - 96 Deg F
Cat Temp - 1670 Deg F
Water Temp - 185 Deg F

Fully warmed up & at idle (950 rpm) for 10 minutes:
Air Intake - 111 Deg F
Cat Temp - 1164 Deg F
Water Temp - 203 Deg F

sco

Correct... oil temperature isn't in the OBD specs, nor is it one of the proprietary data items available on the '8... probably has something to do with the lack of oil temperature sensor

Oktobernv

Oh yea.....one other thing about my visit to Magic yesterday.


When I asked my service rep if any 2005's had failed engines yet and he said "no, not yet"

My next questions was "what is the difference between the 2004 and the 2005?"

He told me this:

He said that about 2 weeks ago when the Madza engineers were camped out at Magic looking over all the failed engines they took a break and had a sit down meeting with the head tech at Mazda.

He said that my service rep, the Mazda engineer and the head tech at magic all sat down and looked over the 2004 and 2005 specs. He said they tried to find any differences that might help to explain why the 2005's have been immune so far.

He said they did not discover anything that appeared to be that much different. He said that the 04 and the 05 are "basically the same on paper"

So maybe it is just a lack of miles on the 05's so far......or maybe it just takes two good HOT summers before the engines have had enough.

I suppose we can answer that come next July here in vegas.


Rob in Vegas.

clydejmuggs

I don't think you can read oil temp with any tool.

Sco would know.

dannobre

iTrader: (3)

Someone down there should put in an oil temp guage...an see what's up. With the size of the oil coolers, and the coolant temps in the normal range....there shouldn't be an oil temp problem. For my 2Cents...I think the fans should come on at a lower temp. This would help thhe underhood temps as well. I have had some ungodly high intake temp readings driving around town. (160 deg..up to 80 deg above ambient) The coolant temp normally runs around 186 deg driving...but it spikes to 208 before the fans come on.. this chart is for car at IDLE

Engine condition
Fan relay1 Fan relay2 Fan relay3 Fan No.1 Fan No.2

Engine coolant temperature 97°C {208°F} or less
OFF OFF OFF OFF OFF

Engine coolant temperature 97°C {208°F} or more (until 94°C {201°F} or less)
ON OFF OFF Low speed Low speed

Engine coolant temperature 101°C {213°F} or more (until 98°C {209°F})
ON ON ON High speed High speed

A/C and fan switches are on. The refrigerant pressure switch (medium pressure) is off.
ON OFF OFF Low speed Low speed

Engine coolant temperature 101°C {213°F} or more or the refrigerant pressure switch (medium pressure) is on.
ON ON ON High speed High speed

ECT sensor malfunction
ON ON ON High speed High speed

rotarygod

I was hoping for oil temp readings. Oh well. That is something that would be very nice to know. Watch this actually be the source of all problems because it is the one thing no one can monitor. It really wouldn't surprise me.

I'd like to know out of the engines that have been replaced so far, how long was it since their last oil change on average? If there is no correlation to time then I don't know what to say but if they have all gone a long time since their last change, it could prove that their is a long term oil breakdown issue due to the hotter temps. Just brainstorming here.

demob05

...and the owner's manual for the RX-8 (at least the 04 models) specificallly recommends oil changes at @ 7,500 miles!! Is Mazda still sticking behind that?

missinmahseven

I'm still not sold on hot oil being the root cause. Oil has come a very long way from the sludge people fed their cars 30 years ago. Hell even 20 years ago.

I spent 3 years as an aerospace ground equiment wrench. One of the pieces I serviced regularly were gas-turbine generators. Miniature jets, really.. it always struck me how thin the oil is on those.. and keep in mind they spin to about 80,000 rpm, and the temps are rather insane. 10 or 20 weight oil, iirc, usually a shell synthetic like aeroshell. The oil looked like water, almost.

I'm thinking about doing oil analysis on my car every 2 oil changes, see if any eary signs of weirdness creeps in. A couple folks here allready do, and the oil's coming back pretty good, albeit a bit diluted in gasoline.. typical for a wankel.

If the motors are machining themselves to death, it'll show up very early on as high levels of various metals. If there are coolant leakage issues, that'll also show up.

Has anyone here with affected engines ran oil analysis? If so, what's it saying?