Reading Spark Plugs?

[4.6modular]

OK just pulled a few of the plugs on the drivers side and noticed a white film or powder on the end of the plugs. Not the electrode itself but the end that curves around. Whether it's on the end of the electrode itself doesn't white mean lean or hot? They are NGK TR7-IX which is two steps colder then stock and one step colder then TR6's. Also this is with a 2.80 pulley with a HE and Tune.

 

[4.6modular]

any spark plug gurus?

 

[I8URZ28]

possibly a little lean, is it white or light grey ? do you run race gas ? normally light grey to light brown is normal depending on the octane gas you are running and the quality of the fuel. is it just white on the metal contact or is it white all around the electrode (not the porcelin)

 

[4.6modular]

It is white on the ground strap. The porcelin and center electrode look practically brand new. No change in color there.

 

[I8URZ28]

Hmmm. if it is white I mean Not light grey but white then you may be a bit lean but if it is grey then those plugs are OK .also if the porclin center looks brand new that is a good sign that you are not having any serious problems normally really lean conditions can cause the procelin to become pitted or look like there are pieces of melted glass stuck to it.-- which is actually the porcelin beginning to melt. If I were you i'd run your car another couple of hundred miles and check them again. If you run a CAI and aftermarket TB I have heard through the grapevine that these can cause your car to run SLIGHTLY lean but nothing to be alarmed about.

 

[4.6modular]

Thanks I8URZ28. Thats the info. I've been needing. All worries are put to rest though as I dynoed Saturday with a A/F of 10.75-11.8

 

[ScottsdaleSnake]

Quick question....I had the same issue as the OP, but this seemed to occur after I regapped my plugs from 0.035 to 0.032...In the end, the idle was too choppy so I bought new plugs and gapped them back to 0.035 (TR6) and the idle is now back to rock solid, no movement. FYI, the porcelain, electrode, etc. all looked fine...just a white residue on the outside of the contact. My original post is as follows:

Is it common for the plugs to look white around the top part (the curved area that you adjust the gap for) if you gap the plugs too close? At 0.035 the plugs looked great - no white residue; at 0.032 all the plugs have a white residue on them. Any ideas? Could the tune have been "wiped away" by me unplugging the battery too often? Btw, car was previously tuned for proper A/F for my mods. I did just add an O/R X-pipe and catback and those 2 upgrades were not there when I did the tune. Could that be the issue? I assume I should retune the car given the O/R X...correct me if I'm wrong though. Thanks in advance. :rolling:

 

[firemedix911]

If you installed a less restrictive exhaust you could be runnign leanner. Although it is a lot more common to see this issue after LT installs. But it is very possible since you
went to off road pipes.