I thought I'd post this up for general info. I'm not sure what the compression failures on the R3's or series 2 generally are like in the US, but it seems I've had one of, or the, first in the UK.

44,500 miles and compression in the low 6's at 250rpm. The car had been pre-mixed with Pro-tek since the second tank of fuel, oil and filter changes every 3 to 4k, and a number of track days with oil/filter changes immediately before and after in addition to the regular 3 / 4k changes.

Mazda changed the engine for me under warranty no problem, so I have a nice, brand new engine which I'm just running in now. But the failure was a surprise to me and the dealer, given all the extra stuff on the R3 (series 2) to try and prevent low compression ...

How are things with the series 2 in the US?

 

Hey, what oil were you using?

 

While your car received regular oil changes, and pre-mix, did you ever service the ignition system during your ownership of the car? Letting the ignition system fail is the sure way to have a dead RX-8 engine, no matter what series it is.

I changed my coils wires and plugs at the 20k mile mark, just to eliminate the one system that can fail without notice, and kill my engine prematurely. Is it a bit on the overkill side? Yes, but its better than replacing an engine, under warranty, or not.

BC.

 

Wow probably THE nicest Series 2 around and just happens to have an early engine failure.

I've got 25,000 miles on my 2009. No issues yet - but I don't track mine just a street/commute queen.

 

36,000 here, change oil at 5k top off alot, dont premix as series 2 adds more oil, got a decat, run hpde, and auto crosses as much as i can, did bhr coils and plugs at 15k, no issues here at all

 

2011 RX8, 14,255 miles,

Change your spark plugs every 14,000 mile.

Over the past two weeks I've notice roughly six misfires. (six misfires in 300 miles driven) The misfires have NOT triggered MIL,
malfunction indicator lamp.
Although misfires are very subtle and intermittent it is a sign something in the ignition system is starting to fail.

I contacted the local dealer and ask them to download the last ten drive cycles. A drive cycle is key off, key on, key off.

The scan of the ECU misfire log noted four misfires in the last ten drive cycles. Not to bad but still a concern.
six misfires in 14k miles is about as good as it gets regardless of manufacture. according to Industry standard 400+ misfires triggers CEL or MIL.

The dealer is contacting Mazda to see how they would like to proceed with my concern.

Bottom line... The plugs in my car lasted one year and three months. and are covered under 3yr/36 k mi warranty.

 

Just out of curiosity, What prompted you to have the compression tested? Was it running or starting poorly?

 

Are you running a cat?

 

eat well and sleeps well, never smoke nor drink does NOT mean you will never gets cancer. keep that in mind.

in the other words, **** DOES HAPPEN.

at least u got ur stuff for free.

wrong, rotary engine should ALWAYS premix regardless of OMP. sure they updated it because they messed up on the OMP pointing at corners and "forgot" the center and it is better than S1, but if u open an engine up and look at the wear marks, you will know why you should ALWAYS premix.

a few misfire is OK for any engine. newer coils last longer than old, especaially Revision C.

 

Hi,

Yep, it does indeed happen, but via the car equivalent of healthy eating one hopes one can stave off the 'cancer' for a bit longer than was the case with mine.

I am using Mazda Dexelia 5/30 oil exactly as specified in the UK (you need to use it to maintain the warranty here), plugs changed every scheduled service at 12k miles, coils and leads at 20k. (And as mentioned earlier, pre-mix every tank with Pro-Tek since tank 2, and oil / filter changes every 3/4k miles)

I am running a Pettit Catback with the Mazda OEM cat.

I did the compression test primarily to see what effect, if any, some hard track days had. In my case compression was a bit above 7.1 (which came as a nasty surprise) at 250rpm prior to 2 hard track days and down to low 6's (which came as a very nasty surprise) straight after. One could conclude that track days are not massively healthy for the engine. JRX13, maybe I should also stick to being a street/ commute queen (and I still haven't found that illuminated gear ****, by the way ... Though still looking )

Though there seem to be some folks in the UK who've done more track days than me (in S1's) and perhaps don't seem to have suffered in the same way.

So wondered how people were going with their R3's / S2's (we only got the R3 version of the S2 in the UK) in the US market which is much bigger (slightly less than 1,000 R3's were sold in the UK), and whether or not you were getting (m)any compression failures?

 

Wow I'm surprised you still remember about the illuminated shift ****!

Yeah I'm too scared to take my RX-8 on the track. I waited 6 years to get my first RX-8 and don't want to mess it up!

But I have been taking my beater RX-7 for 10 years now. Never premix - just the standard and old school manual metering pump. Started tracking it when the original engine had about 90,000 miles - did that for about 6 years -averaging 5-6 track days a year. Then finally refreshed the engine about 3 years ago due to a chipped apex seal. It still ran good on the track even with that - but the idle was a little rough so I pulled the engine out and rebuilt it during an off season.

 

They seem about as common as hen's teeth, for some reason I can't understand.

I can entirely empathise with your thoughts about your lovely RX8, and you've done incredibly well with your RX7. May your RX8 give you equally sterling service. (I'd put a smilie here, but all the icons have disappeared - Doh!)

 

let me correct myself i most definatly premix before any auto-x or hpde tack day etc, but for street driving i dont. but i dont dirve it much as a DD anymore so not too many tanks dont get premxed, so it usualy always has premix in it

 

My 2009 R3 has 27,XXX miles on it. I purchased it at 24,9XXX miles a little over a month ago (previous owner had all the oil changes done by the mazda dealer every 3-4k miles and I have the records for all of them). I got a compression check done before signing the deal, my results were as follows:

(in kg/cm^2):
Rotor 1: 8.2/8.4/8.5 281 rpms
Rotor 2: 8.3/8.1/8.4 282 rpms

Those compression numbers are on a car that is 100% the same as the day it came out of the factory (however, I do not know how the previous owner drove the car, if she exercised it or just cruised in it). I have a BHR ignition system ready to go in the car as soon as the weather gets warm enough that being in the garage isn't physically uncomfortable (along with transmission fluid, diff fluid, and a few other things like MAF and ESS cleaning). Still searching for pre-mix (not found of the idea of buying massive quantities, but if that's what it takes then I will eventually succumb). I do make sure that the engine gets regular exercise (taken up to 8,000 rpms in 1st and 2nd gear sometimes even 3rd) every single time I drive it (and on Tuesdays and Thursday when I have class at a neighboring university, I take the back roads and give it a good, consistent thrashing).

I've got my fingers crossed and saying my prayers that I my engine will live a long, trouble-free life (or at least be trouble free until I finish up my PhD and get a big-kid job with a big-kid-job paycheck).

 

The part of this I find most interesting is that you seem to indicate that the 2 track days were the downfall of the engine, however, pretty much everything else I've ever read (here and on other rotary forums) says that these engines NEED to be taken up to 8,000 rpms at least once on a daily basis to "exercise" the variable intake system as well as to produce more heat and intake/exhaust gas velocity in order to help remove carbon build up from the engine.

Hmmm....

 

I think the track days likely do have at least something to do with it. I had already taken it on a number of track days before I got the first compression test. But as I had 2 track days a few days apart coming up and a service just before the first one, I thought I'd do a before and after compression test (along with the oil changes, etc), just to see what the effect was. And it was a big drop in compression.

And I guess there's quite a difference between the 'daily beep' once the engine is warm and thrashing round a track for (overall) several hours in a day, where you may be beeping it every few seconds?

 

i would disagree.

i think it is def important to run it hard often not every time, but just one readline wont due much at all it needs to be driven harder.

i have felt this myself quite a few times, that after a few weeks of normal driving then having an autocross event, my car always feels better after the events, idles smoother etc etc. but this is just imo

 

100% agree ^^^
You're not going to clear very much carbon with one redline in first gear a day when you think about it those valves are open for what 2-3 seconds maybe? It's the long hard pulls that really do the work. This is why I try and stick to a "redline day" per week regimen lol

 

Is your hypothesis then that despite doing 44,000 miles in 2 years and numerous track days (during one of which I managed to weld the brake pistons to the steel brake pad backing ... so that's kind of pushing on; managed to eat a new set of RB ET500's in a morning, and put a good dent in a new set of XT's in an afternoon), the cause of my low compression is not driving it hard enough?

It could be, I guess, ... but how do you think that would that explain the compression drop from low 7 to low 6 during a period of a week, 2 hard track days and 1500 road miles?

 

Oh I wasn't referring to your circumstance I happen to believe you had a fluke lol You did what the car was intended to be used for and even though these engines are put together by hand parts will fail plain and simple :-P

 

Oh, OK ... Thanks for clarifying, I was just wondering. I hadn't considered it in that way before. I guess I may (as you say) just have been unlucky and had a rogue one.

And as no-one else is saying theirs has failed, it sounds to have been a genuine rogue! Lucky I caught it under warranty.

Though interestingly a couple more guys in the UK have just contacted me about having low compression measurements on R3's, at around 25,000 miles. Strange.

 

what were your coolant and oil temps during the tracking days?

 

Unfortunately I don't know, as I don't (yet) have things like the nice RB gauges to give me an accurate reading.

All I can say is that the the M'Z Custom nose allows a fair bit more airflow than stock to help with cooling, the Mazda gauges on the dash were showing normal, and the fans were not cutting in for long (or at all) on the slow-down laps. Not very scientific, I know.

Do you think that may, or may have been likely to, have been an issue?

 

just a factory defect. dont worry about it too much.
**** happens. my R3 has about 24k miles on it. everything runs just as good. although I probably gonna change the spark plugs soon because I an hearing some MIAC sound at lower RPM heavy throttle weirdly.

 

Mazda changed my spark plugs today under warranty, 14,900 miles