I put a set of new plugs in my car a little over 200 miles ago. Well I took them out to clean them because they foul so easy because I have extremely rich AFRs(just a theory not for sure). Well I examnined a lower plug and it was cracked. I believe this happened because friday night I ran my car pretty spirited for a little bit and believe that was what did it. Well I say to myself, I'll just get "colder" plugs to retain the heat better because I remember an article on Mazdatrix website, they say that they are better for streetported motors street driven 99% of the time and some occasional hard driving(me). the only problem is they foul easier, which sucks *** for me because my motor still has hot-start problems after nearly 3k on the rebuild. My question is, should I get colder plugs to prevent cracking, but have them foul easier, and take in mind mine foul every 2-300 miles. Or should I keep the normal NGK's until I have no hot-start issues to prevent fouling, but risk the heat cracking the plugs? What to do, what to do....
Thanks in advance.

 

Are you sure it wasn't just a bad plug to begin with? I've driven my car fairly hard for long periods of time, and haven't had any issues cracking plugs. I'd give another plug a shot... if you *keep* cracking plugs, start looking at other options, but with just one case, I'd suspect a bad plug.

-=Russ=-

 

Point taken, I'll keep an eye out for it.

 

yup....ive had a cracked ngk plug....... i noticed it when i took it out of the box...... so, i always check now before i purchase them!!!! although i dont see a cracked plug hurting anything!

 

Are we talking about NGK spark plugs?
What specific NGK spark plug model?


-Ted

 

NGK BUREQ7 I'm not sure if that is the exact serial code(BUREQ) but it is definatly a 7. Non platinum as well.