okidoc

I had a rough running condition on my 95 3.0, it was an intermittent miss at idle and through the RPM the range. After changing the cap and rotor I decided to change the plugs. I was surprised to see half the ceramic insulator on the old NGK missing on cyl #6. Since I bought the truck used I can only assume that it was lost in the cylinder and hopefully shot out the tailpipe before it did much, if any damage.

Anyway I replaced it with new plugs and all is fine. My vacuum gauge is still steady so, I don't have bad valves or rings.

I thought this would just be fuel for thought for when these conditions present themselves. And a reminder to check the simple things.

One thought though, what condition other than detonation causes the insulator to crack? This 3.0 runs really strong without pinging or noise or any other complaints. Could it be the result of defective materials or is there something else to look for?

Billf6531

My guess would be it broke when whoever installed the plugs, gapped them, or dropped it. If anyone other than the owner did it, I'm sure, based on experience, that they would have just installed it anyway. After all, what customer ever pulls the plugs to check the quality of the work. If they had the ability to check the plugs, they would have done it themselves, correctly, in the first place. JMHO.

Dr. Zhivago

[Off topic]

With regards to Bill's signature. I would have kept the old truck, too...

G

[/Off topic]

Billf6531

Well, it's a company truck. The day before the five year power train warranty runs out, it's traded in for a new one. It's not practical to own non-warranty vehicles for business purposes. That, and only 50% depreciation after five years makes perfect accounting sense. I only wish Toyota wouldn't cater to the mall-cruising crowd so much, but l guess that's where the majority of the money is.

However I've been looking for a mint, low mileage 98-00 Limited, in Calgary, to purchase, lift a little, and enjoy as a personal 'beater'.