Interestingly, I lost power trying to start from a red light. Car would barely hit 20 mph, and felt like trying to take off in 5th gear. Excessive vibration and blinking CEL, excessive noise and vibration at idle.

For this 05, the 1st engine failed around 33k. 2nd engine was mother nature, flooded intersection at 39k in Dec 2012. Drove it across the country with fresh oil in 2014, and it bogged down today at 45k. Not a lot of miles, even for a reman.

Have BHR ignition, and premix with ZX-2SR (mineral base, no residue).

If it is the engine again, it would not make sense to keep replacing it on this platform.

Also this week, a car knocked my motorcycle over in a parking lot while I was at work. But honesty prevailed and the driver informed me. It is in unridable condition due to the damage.

Mentally I am unfazed. Things just break or get broken, not a big deal. I am temporarily working in the south--difficult or impossible to get service on the weekend. Will have to wait for answers next week.

Trying to stick with Mazda as they have done a pretty good job, but they don't even have the new generation available. Rental is 15 gmc yukon, all the latest Bluetooth crap, very comfy.

 

That doesn't sound like engine failure.

That sounds more like you had one or more plug wires pop free of it's plug.

 

You are correct and I was wrong in my assumption. The engine was fine. The CEL code was in regard to ignition (P0300). Info as follows, all reports attached as pdf files:

I had the dealer verify all wiring is tight and no wires were loose. After that was assured, I authorized a compression test to ensure the motor was ok. I was advised to pay for new coils and spark plugs at that point. That was confusing... 6k miles and ignition failure already? Obviously, I bought them from elsewhere than a Mazda dealership, but had the new spark plugs and GM Yukon coils (ACDelco D585 / GM 10457730) mailed to the dealership directly. Compression test result attached:

Link: "Judgment of Engine Compression" pdf file

Rotor 1:
1 - 850 kPa
2 - 840 kPa
3 - 890 kPa
RPM 236

Rotor 2:
1 - 800 kPa
2 - 800 kPa
3 - 800 kPa
rpm 2228


It turned out, 2 out of 4 ignition coils were bad. I spoke with the service technician directly, who explained the use of an electric field measuring device to test for bad ignition coils. In addition, OEM rx8 coils were installed first to verify this diagnosis, before plugging in the new set of Yukon coils I shipped.

The old spark plugs were thrown away before I could intercept them. According to the service tech, my old spark plugs were "black" in color and "heavily corroded".

I do have the old Yukon coils, although there's nothing I can test to my knowledge:


The driving profile and mileage before Yukon coil failure does not make sense to me. The whole point of an aftermarket ignition is to provide reliability above OEM, and the OEM provides at least 10,000 miles before noticeable power degradation. Hopefully, someone has a clue as to what caused the black spark plugs and ignition coil failure.

39k miles (sep 2012) - bhr ignition installed with new coils and new spark plugs.

39k miles (dec 2012) - water flooding and 3rd engine installed

43k miles (june 2014) - 2,200 mile road trip

45k miles (oct 2014) - ignition coil failure

Driving profile: 1 or 2 drives per month to pickup propane/charcoal/big items. Battery disconnect switch in use. Each startup has a reset fuel trim.

Oil: Castrol GTX 5W-20
Premix: 4 oz / fill

Commute distance to work: (sep 2012 - june 2014) - 1.9 miles
Commute distance to work: (oct 2014) - 10.5 miles

Mods:

VFAD removed
Resonance chamber capped
BHR ignition
Exhaust - dec 2012 - jan 2014: straight
Exhasust - jan 2014 - present: Magnaflow mufflers

There could be something fishy going on after the water flooding incident. But as far as I can tell, things were back to normal prior to my drive trip across the country. A few corroded parts here and there.... Other than insurance repair on major items, I bought a new Bose door amplifier from water corrosion but nothing more serious after several years.

The car sounds and feels new after picking up today. I am surprised that I didn't notice the degradation before, but my driving is so seldom that my subjective feel cannot be trusted.

View the service invoice notes:


Link: Service invoice and notes pdf

 

Interesting. If two coils supposedly failed, I'd say that neither of them actually failed and that the testing was flawed.

I think your spark plugs were the only problem. Were they non-stock plugs? What kind of gas do you use? Do you flood it often? I can see that you only put on 4k miles from 2012 to 2014, was the car sitting in a humid environment for any long period of time, perhaps accumulating water and allowing internal corrosion?

 

Leading = Lower in engine......shorted out in flood?

 

-stock spark plugs
-gas always Top Tier, best available (91 in CA, 93 in FL).
-humidity was not an issue in CA, but is an issue in FL (50%-90% humidity in summer, with frequent thunderstorms/tropical showers)
-never flooded

CA road environment: 65 mph freeway access, 2nd gear onramp redlines, etc.

FL road environment: 45 mph, stoplight to stoplight. No freeways in the vicinity. Some redline in 1st gear, little bit of load in 2nd on occasion.

2012 (CA): Rarely used. Pulled indoors every few months for cleaning, charging the battery, etc. Always idled for coolant to reach the middle temp before shutting down.

2013 (CA): 8 total fillups.

2014 (CA - FL): Two weeks usage in CA (91), then drive and 6 fillups total in FL (93) from June to October, when I got stranded.

 

According to a service manager on the phone, it was the front bank coils, both leading and trailing.

 

When I did an LS2 coil conversion on my MSM, I did a lot of research on coil options, as not all D585/Yukon/LS2 coils are created equal. There are just as many, or more, counterfeit or low quality options for them than there are for oem-style RX-8 coils.

Everywhere I looked, it was very common to have 1-2 coils fail VERY quickly if you don't pay top dollar for confirmed OEM coils. There are 2 brands, ACDelco being one, which are the OE supplier, and Richporter (visible in your pic) isn't one of them. If you buy anything else, basically the rule I was finding was "buy 6, and you should have 4 good ones".

So premature coil failure isn't something shocking here.

 

I'd suspect that one of them was a failing coil, and the rapidly fouling conditions at the spark plug caused the other to fail from being unable to punch through the fouling, which just starts overheating the coil rapidly.

Charles may have a better theory though.