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2 (inner core) broken NGK spark plugs on 2nd rotor after 30.600 mls (incl. pic's)....
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This is what I wrote to NGK-Europe in Germany..................
Dear Madam, Sir,
I am the owner of a MAZDA RENESIS RX-8 HP WITH ROTARY ENGINE (231hp) of 2008 (VIN nr. JMZSE173650121340); purchased new; now 57.000 kms on the odometer. My exhaust tips were always very clean / hardly no carbon deposits in/on the tips (I premix synth. oil 1:250 since new)....however since the tips became slightly blackish on the inside I immediately had doubts about the ignition system; expecting the ignition coils (49.000 km) as the problem. However they were ok/excellent, but by renewing the coils, leads and plugs (all after a running period of 49.000 km) I noticed that on the 2nd rotor (closest to the firewall), after popping of the leads, from both Leading and trailing sparkplugs the inner core was broken and left in the leads. Before disassembling the ignition system the performance of the engine both at high rpm and idling was excellent. This is a dangerous situation as it can damage the catalysator and also the engine. In my opinion the broken core's caused the combustion not to be proper/efficient for the last 1.000-1.500 km's. My problem is that the NGK spark plugs-types adapted are exact conform the requirements both of Mazda and NGK Both sparkpugs broke down at 49.000 km which is within the 60.000 km replacement interval Mazda requires. SOME DATA ABOUT MY DRIVING CONDITIONS: * Generally medium distances from 50-150 km (one way); never less than 5 kms; sometimes 20 kms; no high rev's during warming up to 80 degr. C (I have an engine sump oil temp meter) * Sump oil temp. 90-95 (max. 100 in peak hour traffic) degrees C in summer; 85 degrees C in spring and autumn; in winter the car is not used. * Engine oil synthetic 5W30/5w40 * Moderate drive style; never to low in gears; never the high rev's of 8.000 rpm etc. (I am 73 years of age but also have a Lotus Esprit Turbo SE and a Classic Saab 900c) * I am very cautious with this fantastic RX-8 HP and when (dis)mounting the spark plugs I always pay utmost attention to "hand screw in" and caring not to hit the porcelain isolator. I HAVE ENCLOSED 7 LINKS OF PICTURES OF THE DAMAGED SPARK PLUGS. Please advice what to do; was this only a unlucky event (which I could accept immediately) or is there some other reason. Please eventually consult your Japanese collegues of NGK as they have a broad experience and knowledge (of problems) with the Rotary Engine of the MAZDA RX-8
Best regards, Rudolph Wolven
Note: the spark plugs were not stressed by "towing leads".....they were attached flexible.
* This was the reply of NGK after couple of days (Dutch translated to English by Google-translate)
Dear Sir Wolven
Thank you for your message. We regret the situation that you have described in great detail.
We can not and must not, however, on the basis of these data and the you that was sent pictures give a ruling on the cause.
If your vehicle data matches the data below, the correct spark plugs for your car are: RE8C-L + RE9B-T.
If the correct spark plugs are used, may be examined at the technical center of NGK spark plugs, to assess whether they have functioned properly.
For this you can spark plugs including offering your report / report at the store where you purchased the corresponding spark plugs.
The point of sale the spark plugs with the necessary forms can be sent directly to NDA.
Once the investigation is completed there will be prepared a report and sent to you.
PS: Because of your interest in technique we refer you to our new technical platform: http://www.tekniwiki.com
On this new site you will find a lot of technical information tips.
With best regards / Mit freundlichen Gruessen / Sincerely,
KCC department (Customer Contact Center)
NGK Spark Plug Europe GmbH
* My reply on the anwer/conclusion from NGK........
Dear "Afdeling KCC (Klant Contact Center)",
Thanks for your quick reply, however it is disappointing and not of great help for me since it more or less reads like "a standard reply with very few and irrelevant commitment".
It is in my opinion considered as irrelevant commitment because you said........"Indien de juiste bougies zijn gebruikt,"........whereas from my pictures you could clearly see that I used the right types of NGK spark plugs.
Your reply furthermore is not very practical since I generally purchase my NGK spark plugs via internet in the USA or UK and (still having 2 more sets of spark plugs in store) do not know exactly where/when I ordered these specific plugs in the USA/UK.
Furthermore I can not understand why these faulty plugs have to be sent to you via an extra intermediate link/dealer (causing misunderstanding / evt.missing shipments and unnecessary extra costs) and can not be send to you directly for judgement.
On the basis of your unusable reply I will leave the problem as it is.
However on a short notice I will publish the matter of the broken NGK spark plugs on the international RX-8 owners forums in the USA, UK, Germany and the Netherlands (which I all frequently vist and post as a member) as a serious warning since this kind of damage with the spark plugs , in the case of the Rotary Engines of the RX-8 (not with 4 stroke engines) principally always cause a total catalysator and engine failure on a short term with total repair costs of approx. Euro 10.000,-.
My fellow RX-8 owners need to be aware of this hidden catastrophic danger.
11-01-2016, 06:09 PM
