crazyassracer

Changed the sparkplugs in my car and noticed the three plugs on the passenger's side cylinder bank looked normal for 98,000 miles, but the three plugs on the driver's side bank looked excessively worn (worn down and misshapen electrodes).
My best guess is that the driver's side exhaust doesn't flow as well as the opposite side, and the higher temps are causing more aggressive wear.
My exhaust is stock except for the Borla muffler.
Anyone else notice this on their 4.0?

basketballord

I'm assuming at 98,000 that you were the last one to put the plugs in? So they were the same plugs and installed at the same time on both sides? What kind of plugs were they?

Maybe your coil is messed up. I don't know if there is a way to test your coil, but maybe you could start there.

crazyassracer

All six plugs were the original factory plugs.

I dont know enough about the coil pack to say that it would affect one bank only. It looks like it groups the plugs by twos, so 3 odd plugs would be... odd.
But I'm honestly only guessing.

MEK

I believe this is normal.........check out the link:

http://www.miracerros.com/mustang/sparkplugs.htm

crazyassracer

Wow, I aint never heard of that before. Makes sense I guess.
Thanks for the input. Is that author reliable?

MEK

I actually first heard of this on one of the forums, but I couldn't remember which one so instead of searching forums I just did a quick google search because I knew this was out there. If you search around, you should be able to find more info on this.

Check your original stock plugs and see if in fact they have different part numbers on them?

basketballord

interesting! good find MEK

laterider

^^^^^
+1