R3 Engine Compression Failure in UK
03-08-2013, 12:59 PM
#27
RX8R3Rod.. The 36,000 mile plug-change interval is completely unrealistic.
The cold start and cold idle soo much better with the new plugs, NIGHT and DAY different.
The amount of old ash on the plugs was equivalent to that of plugs out of an old ford V8 after 60,000 miles.
If the plugs are neglected, the cat will be junk in two years.
Note. I top off the oil every tank, and shift at 7k to 8k Every shift.
The cold start and cold idle soo much better with the new plugs, NIGHT and DAY different.
The amount of old ash on the plugs was equivalent to that of plugs out of an old ford V8 after 60,000 miles.
If the plugs are neglected, the cat will be junk in two years.
Note. I top off the oil every tank, and shift at 7k to 8k Every shift.
03-14-2013, 09:03 AM
#28
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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?
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?
03-14-2013, 10:06 AM
#29
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Well I just wanted to add my details as another data point, hope it helps someone.
Bought my R3 with 47k miles on the clock, had it compression checked before I bought it and it passed. It was serviced regularly and the oil changed every 3-4k miles. I changed out the ignition system (plugs, coils, etc) after I bought it since I didn't know if the previous owner did or not, but from the looks of the old plugs I would say not. Since then I've put 12k miles on it and also changed the oil three times, and done 4 or 5 track events. I don't usually premix on the street but for the track I added a few ounces.
Anyway, at 59k miles I dyno'd it at 179whp (on a dynojet) which seemed about normal, maybe a tad on the low side? Motor was pulled (not because it had any particular problem) and here's what the rotors and housing looked like. The rotors have a fair amount of carbon built up, the housings look not too bad though.
I know this probably doesn't help you but at least you have some other data to compare to. Sorry about your R3, it looks awesome, hope the new engine lasts you much longer. (Love your color and blacked out fog trim)
Bought my R3 with 47k miles on the clock, had it compression checked before I bought it and it passed. It was serviced regularly and the oil changed every 3-4k miles. I changed out the ignition system (plugs, coils, etc) after I bought it since I didn't know if the previous owner did or not, but from the looks of the old plugs I would say not. Since then I've put 12k miles on it and also changed the oil three times, and done 4 or 5 track events. I don't usually premix on the street but for the track I added a few ounces.
Anyway, at 59k miles I dyno'd it at 179whp (on a dynojet) which seemed about normal, maybe a tad on the low side? Motor was pulled (not because it had any particular problem) and here's what the rotors and housing looked like. The rotors have a fair amount of carbon built up, the housings look not too bad though.
I know this probably doesn't help you but at least you have some other data to compare to. Sorry about your R3, it looks awesome, hope the new engine lasts you much longer. (Love your color and blacked out fog trim)
03-15-2013, 01:35 AM
#30
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Original plugs were changed at 30,000 miles - they looked pretty average compared to what I've seen here, but I bought the car with 1,000 miles on it and it probably had a LOT of cold starts / short trips.
Recently changed the 2nd set of plugs at 68,000 miles, and they could have gone farther. No excessive wear and they seemed relatively clean (better than the originals). The replacement plugs did not change the running quality at all.
Running 4 oz Idemitsu per tank, redline it once every other day or so. 20% town driving / 80% highway driving.
Last edited by PeteInLongBeach; 03-15-2013 at 01:37 AM.
03-15-2013, 04:39 AM
#31
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Ohayo, sorry to hear about your engine. But great to hear it's a warranty replacement! It might be worth pre-mixing, though it clearly didn't save my engine from early demise. But it might have delayed it ... Who knows? Did Mazda say what had failed?
Scorchjeff, thanks so much for sharing your additional data point (and very kind comments on the car). There's very little data we seem to have on S2's, so every bit helps the owners community. I would have thought 179 at the rear wheels wasn't really too bad after 59k miles? And great pictures thanks. The housings look really good don't they? But it's difficult to imagine the rotors were from the same engine when you just look at the picture. Is it ok if I share these pictures with the owners club in the UK? From what I understand, pre-mix is meant to help prevent carbon build-up, so do you think it might help after your rebuild? It'll be great to see what hp you get after the strip-down!
Peteinlongbeach, I envying your plug life. Maybe it's your 80/20 driving pattern that gives you such good results?
Scorchjeff, thanks so much for sharing your additional data point (and very kind comments on the car). There's very little data we seem to have on S2's, so every bit helps the owners community. I would have thought 179 at the rear wheels wasn't really too bad after 59k miles? And great pictures thanks. The housings look really good don't they? But it's difficult to imagine the rotors were from the same engine when you just look at the picture. Is it ok if I share these pictures with the owners club in the UK? From what I understand, pre-mix is meant to help prevent carbon build-up, so do you think it might help after your rebuild? It'll be great to see what hp you get after the strip-down!
Peteinlongbeach, I envying your plug life. Maybe it's your 80/20 driving pattern that gives you such good results?
03-15-2013, 09:31 AM
#32
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Scorchjeff, thanks so much for sharing your additional data point (and very kind comments on the car). There's very little data we seem to have on S2's, so every bit helps the owners community. I would have thought 179 at the rear wheels wasn't really too bad after 59k miles? And great pictures thanks. The housings look really good don't they? But it's difficult to imagine the rotors were from the same engine when you just look at the picture. Is it ok if I share these pictures with the owners club in the UK? From what I understand, pre-mix is meant to help prevent carbon build-up, so do you think it might help after your rebuild? It'll be great to see what hp you get after the strip-down!
Anyway, the dyno at 59k was done in freezing temps so the actual "corrected" whp should be somewhere around 174 I think. I'm no dyno expert so I'm just going by what I was told that day. I'll let you know how the project comes out =)
03-15-2013, 03:34 PM
#33
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Pre-mix is primarily meant to 'lubricate' it will not 'prevent' carbon/soot build up.
scorcherjf, thanks for the pics (although for me slightly blurry), your housings look in good condition, so does the iron for 100,000+ KMS....although closer inspection needed to confirm actual physical condition.
Remember, Mazda also started to coat Series 2 Rotors from 2009 production (there is no VIN changes available) with a black surface coating, so they look more carbon-ed up (not saying your Rotors does not have any soot as it clearly does, like ALL Rotaries every made).
Just curious to know what you believe is 'worse shape'?...
scorcherjf, thanks for the pics (although for me slightly blurry), your housings look in good condition, so does the iron for 100,000+ KMS....although closer inspection needed to confirm actual physical condition.
Remember, Mazda also started to coat Series 2 Rotors from 2009 production (there is no VIN changes available) with a black surface coating, so they look more carbon-ed up (not saying your Rotors does not have any soot as it clearly does, like ALL Rotaries every made).
Just curious to know what you believe is 'worse shape'?...
03-15-2013, 04:15 PM
#34
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Sure you can share them. I was a bit puzzled as well. The rotors were in much worse shape compared to the housings. I'm not sure what kind of life my car had before I got it but I suspect it was mostly highway driving. As for why there's such build-up on the rotors, I'm not sure if it's because of the highway driving before I got the car, or my track days on it after I got it (or maybe it's just a combination of both). The spark plugs were pretty worn out when I did replace them at 49k miles. I think one was even not firing because it was rusted beyond recognition... I have pics of them somewhere if you want to see. Also, I pulled the cat to check and it's in quite good condition (have pics as well).
Anyway, the dyno at 59k was done in freezing temps so the actual "corrected" whp should be somewhere around 174 I think. I'm no dyno expert so I'm just going by what I was told that day. I'll let you know how the project comes out =)
Anyway, the dyno at 59k was done in freezing temps so the actual "corrected" whp should be somewhere around 174 I think. I'm no dyno expert so I'm just going by what I was told that day. I'll let you know how the project comes out =)
First of all, I'd like to echo what was said above - thanks for the pictures. The lack of data from SII cars is an ever present concern to me, so every data point helps! I'm not sure, but did the SI cars start to fail early on like in 2004 and 2005, or did they start to have problems around 2008 (I've read 2 or 3 threads about engines being dead, all posted around 2008, for cars that were from 04-05)? If the later is the case I sincerely hope that the SII doesn't experience the same delayed phenomena.
I would love to see more pictures of your engine, as well as of your cat. I could use a good reference point of what a GOOD cat looks like before I go and have a look at mine before the autocross season starts.
EDIT: As Mr ASH8 has stated above me, pre-mix is to lubricate the engine, not prevent carbon. However, what has been seen and reasonably well documented, is that running pre-mix makes the carbon that does build up "softer."
03-16-2013, 05:03 PM
#35
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Thanks for the permission to share - greatly appreciated. And yeah, if you have any more photo's it'd be great to see them. 
As poacherinthezoo said, every data point helps. And we don't have many.
There were less than 1,000 R3's sold in the UK, and (I'm guessing that) there are less than 20 or 30 on the owners club, based on evidence of postings. Of those, 3 have failed compression tests, and a couple of other owners seem to think theirs might well fail if they did the test. But of course this is nothing like a valid sample.
Of the ones that have failed, mine was 2 years old and 44k, and one was around 3.5 years and something like 21k. But what we don't know, of course, is what the other R3's are doing re compression. They might mostly or all be OK.
All I can say is in my case, compression dropped by around 1.0 after 2 hard track days, and perhaps 1500 miles, with full oil and filter changes before and after both track days, and with hefty doses of premix as Pettit recommends. So that does make me wonder ... But it might be nothing, of course, as all one data point can do is disprove a theory.
And yes, that was my understanding too, that pre-mix helped soften up the carbon and so (somehow) helps prevent build-up. Or I guess at least makes it a bit easier to get rid of to some extent with things like Seafoam?
As poacherinthezoo said, every data point helps. And we don't have many.There were less than 1,000 R3's sold in the UK, and (I'm guessing that) there are less than 20 or 30 on the owners club, based on evidence of postings. Of those, 3 have failed compression tests, and a couple of other owners seem to think theirs might well fail if they did the test. But of course this is nothing like a valid sample.
Of the ones that have failed, mine was 2 years old and 44k, and one was around 3.5 years and something like 21k. But what we don't know, of course, is what the other R3's are doing re compression. They might mostly or all be OK.
All I can say is in my case, compression dropped by around 1.0 after 2 hard track days, and perhaps 1500 miles, with full oil and filter changes before and after both track days, and with hefty doses of premix as Pettit recommends. So that does make me wonder ... But it might be nothing, of course, as all one data point can do is disprove a theory.
And yes, that was my understanding too, that pre-mix helped soften up the carbon and so (somehow) helps prevent build-up. Or I guess at least makes it a bit easier to get rid of to some extent with things like Seafoam?
03-16-2013, 05:40 PM
#36
Never run a rotary engine without a way of monitoring the coolant temps At least. You really really shouldn't track the car without temperature monitoring.
Also keep the rpms to 8.2k. Flame suit on........
Really good of y'all to share these pics and info. Sorry for the hard lessons in learning about this engine.
Also keep the rpms to 8.2k. Flame suit on........
Really good of y'all to share these pics and info. Sorry for the hard lessons in learning about this engine.
03-16-2013, 09:00 PM
#37
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Here's some more pics that I have... they're not the best, wish I had taken more. Again, these were at 59k miles.
Also, here's the pics of my old spark plugs at around 50k miles. From the looks of them the first owner didn't change them lol. Picture of catalytic converter at 50k miles too. Copy of my compression test before I bought it at 47k miles as well.
Also, here's the pics of my old spark plugs at around 50k miles. From the looks of them the first owner didn't change them lol. Picture of catalytic converter at 50k miles too. Copy of my compression test before I bought it at 47k miles as well.
03-17-2013, 09:23 AM
#39
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Honestly, from the little we can see in your pictures, and the results of your compression test, I would have to say that Mazda was very successful in improving the engine in the Series II cars.
How many Series I engines from '04 through '06 will look like that when taken apart at the same mileage, and give those results during a compression test?
BC.
How many Series I engines from '04 through '06 will look like that when taken apart at the same mileage, and give those results during a compression test?
BC.
03-17-2013, 10:32 AM
#40
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From looking at the picture in your original post, do you have a screen in front of the oil coolers? Also, the custom nose seems to have a smaller area than the OEM bumper when looking at the lower lip area (the middle section without a screen).
03-17-2013, 12:32 PM
#41
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Honestly, from the little we can see in your pictures, and the results of your compression test, I would have to say that Mazda was very successful in improving the engine in the Series II cars.
How many Series I engines from '04 through '06 will look like that when taken apart at the same mileage, and give those results during a compression test?
BC.
How many Series I engines from '04 through '06 will look like that when taken apart at the same mileage, and give those results during a compression test?
BC.
With those compressions it actually does not get any better than 'good'.
Also note the all new alloy Oil Pump in orange tray (first OP pic on RX-8 club).
If Oil Pump was turned over you would see the outtake oil exit hole/seal for Oil Cooler line, also note the only pressure relief Piston and Spring area (S2 does not have a rear By Pass Valve).
So why was this engine pulled again....
03-17-2013, 03:28 PM
#42
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Really excellent pictures thanks scorcherjf!
I do have a screen (looks like chicken-wire; big holes) in front of the two oil coolers but would that affect air-flow into the coolers that much? Especially as the duct hole on the M'Z Custom nose is a little bit bigger than the OEM one?
The M'Z Custom nose 'grille' area is deeper than the OEM one, and so I would have thought it would let in more air. And remember there's no 'moustache' to block any of the grill as in the OEM one. Even if one allows for the 'under-grille' section in the OEM nose, it still looks to me like the M'Z basically has a bigger hole (you know what I mean).
I think these pictures sort of show this. Well, the best I had to hand, anyway of OEM v later m'z custom nose ...
And maybe I should get an RB gauge kit then before trying the new engine on track again. Thanks for the tip oldragger!
I do have a screen (looks like chicken-wire; big holes) in front of the two oil coolers but would that affect air-flow into the coolers that much? Especially as the duct hole on the M'Z Custom nose is a little bit bigger than the OEM one?
The M'Z Custom nose 'grille' area is deeper than the OEM one, and so I would have thought it would let in more air. And remember there's no 'moustache' to block any of the grill as in the OEM one. Even if one allows for the 'under-grille' section in the OEM nose, it still looks to me like the M'Z basically has a bigger hole (you know what I mean).
I think these pictures sort of show this. Well, the best I had to hand, anyway of OEM v later m'z custom nose ...
And maybe I should get an RB gauge kit then before trying the new engine on track again. Thanks for the tip oldragger!
Last edited by RX8R3Rod; 03-17-2013 at 04:28 PM.
03-18-2013, 04:30 PM
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Yikes! I don't even want to think about what my spark plugs look like since they haven't been changed yet and I'm at 27,XXX miles! Makes me want to go outside right now and change them! I just need one day with above-freezing temperatures already, if I can't get that in the next 2 weeks I'm going to just suck it up and change them in the cold (I'd prefer not to, as I would much rather take my time and actually enjoy the experience).
03-20-2013, 01:27 PM
#45
All I can say is in my case, compression dropped by around 1.0 after 2 hard track days, and perhaps 1500 miles, with full oil and filter changes before and after both track days, and with hefty doses of premix as Pettit recommends. So that does make me wonder ... But it might be nothing, of course, as all one data point can do is disprove a theory.
03-20-2013, 01:57 PM
#46
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/\ At a guess without seeing naked engine, I would call the compression loss to either fractured Apex Seal and or Side Seal.
RENESIS reliability is really not there @ sustained high RPM (particularly in track racing), IMO if Red-line is reduced by owner, engine reliability improves.
IMO going over 8000 RPM on an engine with over 50K miles is asking for trouble.
And please I am not having a go at the RX8R3Rod for what he may or may not have done @ that time...just my opinion and observation.
RENESIS reliability is really not there @ sustained high RPM (particularly in track racing), IMO if Red-line is reduced by owner, engine reliability improves.
IMO going over 8000 RPM on an engine with over 50K miles is asking for trouble.
And please I am not having a go at the RX8R3Rod for what he may or may not have done @ that time...just my opinion and observation.
03-21-2013, 05:36 PM
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/\ At a guess without seeing naked engine, I would call the compression loss to either fractured Apex Seal and or Side Seal.
RENESIS reliability is really not there @ sustained high RPM (particularly in track racing), IMO if Red-line is reduced by owner, engine reliability improves.
IMO going over 8000 RPM on an engine with over 50K miles is asking for trouble.
And please I am not having a go at the RX8R3Rod for what he may or may not have done @ that time...just my opinion and observation.
RENESIS reliability is really not there @ sustained high RPM (particularly in track racing), IMO if Red-line is reduced by owner, engine reliability improves.
IMO going over 8000 RPM on an engine with over 50K miles is asking for trouble.
And please I am not having a go at the RX8R3Rod for what he may or may not have done @ that time...just my opinion and observation.
I don't want to de-rail this thread with my question (perhaps better suited to PM but I bet there are others out there with the same question), but inquiring minds want to know
. I'm not a rotary expert, hell I'm not even a mechanical engineer or all that handy with a wrench, so I'm trying my best to understand what you guys - the highly experienced and exceedingly well qualified forum members - have to say. What exactly is it about the design/construction of the RENESIS engine that makes you feel that going past 8,000 RPMS is asking for reliability problems? I'm guessing based on the previous lines in your post that it has to do with the apex and/or side seals.
Also, can please define the phrase "sustained high RPMs" as you used it? Are we talking about staying above 8,000 for more than 30 seconds at a time? Spending a total of 2-3 minutes over 8,000 rpms within an hour time period? I just want to make sure I'm on the same page.
It is my assumption (we all know what happens when you assume...) that mazda put the rev limiter at 9,000-something for a reason; presumably based on the results of extensive testing (in my field, we are required to do extensive and exhaustive testing on everything, but obviously it's not really fair to compare the pharmaceutical industry to the automotive industry).
Thanks for clarifying
03-22-2013, 12:01 PM
#49
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I don't want to de-rail this thread with my question (perhaps better suited to PM but I bet there are others out there with the same question), but inquiring minds want to know . I'm not a rotary expert, hell I'm not even a mechanical engineer or all that handy with a wrench, so I'm trying my best to understand what you guys - the highly experienced and exceedingly well qualified forum members - have to say.
What exactly is it about the design/construction of the RENESIS engine that makes you feel that going past 8,000 RPMS is asking for reliability problems? I'm guessing based on the previous lines in your post that it has to do with the apex and/or side seals.
Also, can please define the phrase "sustained high RPMs" as you used it? Are we talking about staying above 8,000 for more than 30 seconds at a time? Spending a total of 2-3 minutes over 8,000 rpms within an hour time period? I just want to make sure I'm on the same page.
It is my assumption (we all know what happens when you assume...) that mazda put the rev limiter at 9,000-something for a reason; presumably based on the results of extensive testing (in my field, we are required to do extensive and exhaustive testing on everything, but obviously it's not really fair to compare the pharmaceutical industry to the automotive industry).
Thanks for clarifying
. I'm not a rotary expert, hell I'm not even a mechanical engineer or all that handy with a wrench, so I'm trying my best to understand what you guys - the highly experienced and exceedingly well qualified forum members - have to say. What exactly is it about the design/construction of the RENESIS engine that makes you feel that going past 8,000 RPMS is asking for reliability problems? I'm guessing based on the previous lines in your post that it has to do with the apex and/or side seals.
Also, can please define the phrase "sustained high RPMs" as you used it? Are we talking about staying above 8,000 for more than 30 seconds at a time? Spending a total of 2-3 minutes over 8,000 rpms within an hour time period? I just want to make sure I'm on the same page.
It is my assumption (we all know what happens when you assume...) that mazda put the rev limiter at 9,000-something for a reason; presumably based on the results of extensive testing (in my field, we are required to do extensive and exhaustive testing on everything, but obviously it's not really fair to compare the pharmaceutical industry to the automotive industry).
Thanks for clarifying
03-22-2013, 04:15 PM
#50
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https://www.rx8club.com/rx-8-discuss...208221/page74/
Look @ post 1838 (approx) by RIWWP, gives an explanation as does the entire thread.
And then perhaps read his excellent threads which are linked in his signature.
Perhaps you can add some details about the Year and Model RX-8 you all own and add in Signature? (go to ''user CP'' top left of Forum Banner...it really helps those who You ask for information to help in future replies by all members.
Welcome to the club.
Look @ post 1838 (approx) by RIWWP, gives an explanation as does the entire thread.
And then perhaps read his excellent threads which are linked in his signature.
Perhaps you can add some details about the Year and Model RX-8 you all own and add in Signature? (go to ''user CP'' top left of Forum Banner...it really helps those who You ask for information to help in future replies by all members.
Welcome to the club.