I noticed that cylinder 3 was being rather noisy especially at a cold start. I pulled the spark plug and noticed that the porcelain had cracks on it. This was the only plug that was cracked and I went ahead and replaced it hoping that was the source of the noise. The noise is still there even with the new uncracked plug. What is it that caused the porcelain to crack? What could I look for that is making the noise and ultimately seemed to cause the cracking on the spark plug?

These are rather new NGK TR55s gapped at .050 wuth taylor OVC wires. Also the opti has 72K miles on it. Valvetrain has never been touched.

I have no idea what could cause this.

Thanks

 

How exactly did you notice cyl # 3 being noisy? cracked plug is usually done when installing them.. They are pretty fragile if any side load has been placed on them.. or if they were dropped at any point.. might have a exhaust leak!

 

I noticed the noise when I was standing next to the engine bay while the car was running. I always wait a few minutes after I start it up before driving, especially when it hasn't ran for a few days. I always do this and I have had these plugs in for about 1K miles without noise so I am 99% positive that I didn't overtorque them. What do you mean by dropped?

 

As in physically dropped on the floor.. do you have headers?

 

I have Hooker LTs. Thats a good point, it could be an exhaust leak. Are there any tell-tale signs I could look for?

 

I would check your slip fit tube.. look for black soot... and burnt plug wires.. they will make a ticking sound if they are arching.. are they Over the cover wires? or under the headers? Go over your header bolts again as well.. just to be sure.. they do somtimes loosen up..

 

They are ovc wires. I'll check out the things you mentioned. Thanks a lot.