In case any of you are new to heat ranges and "reading" spark plugs, I just came across these two websites.

Heat ranges: http://www.sentra.net/tech/sparkplugs.php

Determining heat range for your car: http://grounds-mag.com/ar/grounds_ma...g_spark_plugs/ Yes it deals with lawn mowers, but the same principles apply to us!

 

TomP,

Thanks for the great info.

Don

 

I've always had a hard time reading my plugs. I just keep thinking as long as I don't see any oil or sludge on them I am fine. I've seen the pictures in the chilton manual and haynes but never been able to match mine up to any of them. I had some AC Rapidfire plugs that lasted about 30k and now I put in the AC Platinum plugs in there which seem to run about the same as the others.

What plugs do you run in your car Tom?

 

They're probably fine then; if they were covered in soot, or super-white (like those extreme pictures in the Haynes book), that's when you know something's up.

I used to run Splitfire SF2C's, since 1994, changed them out every year. When I got the MSD 6AL box in 2000, the center electrode started eroding like hell! So I switched to AC plugs, stock, R45CTS. The same thing still happens; go figure. One day I'll try platinum's and see how they hold up.

But other than that, my plugs have always resembled the "optimum operating region" picture in the first (NGK) article I linked to.

 

Tom, your PM box is full. I typed ya a long message that was kindly deleted.

 

Hey Tom maybe you can help me out a little. My rear most pass side plug and my front most driver side plug gets covered in a white ash. I just clean and re-gap them every so ofen. I have 2 broken exhuast manifold bolts both corispond to these plugs. Are these exhuast leaks causing this or is there another problem? I could never find a picture resembles this cloe enough. I have pictres of the plugs at home, but I am at work right now.

The PITA part of this is that I will have to at the very least remove the exhuast manifolds in order to replaced the bokn bolts. I don't really want to pull them as I plan on putting a rebuilt 3.1 in in the next 2 -3 months. Only problem is I think this is what is killing my gas millage as every thing is checking out ok. I even had my injectors cleaned. Takes me about 1/4 of a tank to go 100 miles. It used to take only 1/8 of a tank to do the same run.