My freind has a 94 f-150 I-6 and we went to do a compression check, when we pulled the plug, it was white the only upgrades are a k & n air filter, all stock isnt that wierd any suggestions on why they would be white after 13 years of normal driving?

 

lol, well theirs you problem right there!

I'm pretty sure though white means a lean condition. But with them being that old maybe it's some type of deposit or may even be normal.


Spark Plugs -2

Google "reading sparkplugs" for more info.

 

#1 the ground strap is used to tell heat Nothing else if the color change on the plug is closer to the weld then its too hot, if its closer to the end of the strap then its to cold, In the middle is perfect heat range

#2 The porcelain (not sure on the spelling) on the plug is not used to determine rich or lean it doesnt matter what color it is, You look at this part of the plug with atleast a 10x magnifier and you are looking for silver deposites with will be you piston you can not see this with a naked eye

#3 The base of the plug is used to determine rich or lean from the base to sometimes 2-3 threads around the plug you want a tan color, Black being rich heat color sometimes no color or white being lean