Spark plugs...

[janikphoto]

OK, so I just changed the plugs in the wife's 1998 explorer v6. It has 95k miles and the original plugs. The driver's side plugs had a HUGE gap because the electrode was almost all the way worn down. It looked well used but overall it was pretty clean and healthy looking, the only prob was the little nub of an electrode.

Now we get to the passenger side. These three all looked like each other but not like the three from the driver's side. These three all had a lot more electrode left, it was pretty flat and squared (not worn and rounded over like an old shoe like the driver's side ones), and the very tips that the plug wire attaches to had a sort of white paint on them. Just the very top, it didn't seem to block the wire connector because I saw scrape marks a little further down the top connector. But still, the driver's side ones were a bare metal color, no white top part. Maybe it was a grease that dried there but not on the other three?!?

I'd take photos but I will have to scan them which will take a few days.

So, the question is:

Why were three plugs from each side identical to each other but they didn't look like the other three from the opposite side?

I would think they would either match all six or look much more random.

Also, what was the white paint on the very tip of the part of the plug that connects to the plug wire? It was only on three plugs?!? Why not a factory thing on all six?!?

 

[jimmiecakes]

From the factory, these motors have two different plugs. They're both single platinums but one side has the platinum on the ground and the other on the centre. The little nub erodes off the ground firing plugs and makes them look real bad compared to the positive firing plugs.

IMHO, your best bet for plugs is the Motorcraft AWSF?PP
- the PP stands for double platinum and will work on either side.

Just a reminder that it is always a good idea to gap brand new plugs..... yes, they are pregapped but not necessarily for the intended application.

 

[janikphoto]

Thanks for the info. I already bought and installed some bosch platinum plugs and it seems to run pretty good right now. The engine seems responsive and agressive.

The only thing I don't understand is that the stock ones didn't LOOK like platinum plugs. They looked like an old set of motorcraft plugs that would've come out of a 65 mustang. Big fat electrode, very normal looking and not a little thin piece of metal surrounded by ceramic like all te platinums I've seen. And I remember the pep boys computer even saying that these cars had platinums in it stock. Maybe they have normal-looking plugs with a platinum coating on them.

Oh, and after looking at the plugs again, one side had the worn-down nub and the little arm that gets gapped was also worn and rounded compared to the other side. It was just like one side was working harder than the other. Hmmm, or maybe one side of the engine runs hotter than the other because I know that you can get different temp plugs. Maybe the drivers side needs higher temp plugs to keep from wearing as fast?!?

 

[jimmiecakes]

Nope... both sides need the same heat range. It's just that the design of the ignition system has the spark jump from the centre electrode to the ground electrode on one side and ground electrode to centre electrode on the other.

The condition you have described is very normal and nothing to worry over.