spark plug failure

[daver clasper]

Hi

I have had 2 NGK plugs fail in under 6000 miles. Is this normal for modern ones, as I don't remember this happening back in the day?.

Thanks Dave

[RobPearce]

The modern ones don't like rich running engines. That said, there are apparently different factories for the genuine ones, which make them slightly differently, as well as a lot of fakes out there, so some are better than others.

[GT6DavidMK1]

I gave up on NGK plugs because we had so many failures, switch to DENSO plugs not had a failure since 😉

[Nick Jones]

As mentioned, some NGK plugs seem to suffer insulation failure if wetted by petrol and seem to be more prone when new/nearly new.

I stopped using them after my PI (while still running Lucas injection) killed a whole set one by one.  They looked fine, just didn't spark any more.  Now use Bosch for preference but Denso are fine too.

Nick

[JohnD]

A search for "fake spark plugs" shows that all manufacturers are plagued with them.
Bosch have gone so far as to attach "antifake labels" to their products:
http://www.bosch-aa.com.cn/en/.....t_1.html  (Disconcerting amount of Chinese script on it!)

The differences  between fake and real NGK arae very fine: https://www.slideshare.net/athangal/distinguishing-fake-ngk-spark-plug

While the difrences for Denso are even more subjective: https://www.driven2automotive.com/blog/how-to-spot-fake-denso-iridium-power-spark-plugs-2017/

I suppose the best way is to buy from a reputable dealer, who should take action if  you complain about early failure.
John

[TedTaylor]

Thanks for posting this John.  

While the NGK one is over 5 years old and the low lives doing the faking may have improved their con it is useful as it gives things to look out for.

MUT