So my 98 Durango started acting realy weird when i first started it up in the mornings. once it got warm it ran smooth but untill then u could tell it was missing. So I decided to change the plugs, cap, rotor, and plug wires. The plug wires were the original wires from the factory. 190k miles on them and 10 years.. I think they had about enough. I changed each plug and wire 1 by 1 to be sure i didnt screw up the firing order. i got to the 3rd on back on the right side.(im honestly not sure what number) and the GREEN arrow points to that plug. All the other 7 looked like the RED arrow except for the last on on the left side(again not sure what number it is) and that one is marked with blue arrow.
Can anyone see a problem here????Remember these are exactly how they came out..

 

Red plugs look normal, blue plug looks a bit oil fouled, the green one obviously failed. I'd be checking for debris in that cylinder before running that motor.

 

I agree. The piece that is missing is in the cylinder. You can try to use a stick magnet to try to retrieve it.

Blue I'm not too sure it's oil fouled. This could be the problem with unburned fuel.

The main problem here is you are using spark plugs not designed for this motor. ONLY USE OEM Champion plugs! As a rule of thumb; never put a foreign plug into a American motor.

Get either Champion Truck Plugs or REGULAR Champion plugs and nothing else! Spark plug wires should only be OEM from the dealer or I would recommend MSD Ignition Wires.

 

When I bought the D these were the plugs it had in it.. I havent had to change them untill now because it ran rough when cold. I did out new ones of the same back in but you are right i do NEED to get oem plugs and i will ver soon. As far as the broke off peice i dont know when if broke off... all the carbon on the bottom tells me its been a while so im sure its not still in the cylinder.. Luckily it must have been in small enough peices to slip outa valve and it prolly sitting at the cat.

 

I hope.

Get those plugs out ASAP!

The parts store will give you your money back. Champion Truck Plugs are about $2 a piece and regular Champion Plugs are about $1.35.

What about the wires, cap, and rotor?

By the way the cap and rotor should be OEM or brass contacts. I like MSD. The only problem is that MSD doesn't make all the parts but their partner does. Accel.

 

Durangoguy,

They also make a Champion Truck Iridium plugs. About the same or more expensive than the Bosch plats. Iridium plugs are nearly impossible to foul up due to its super hot pencil sharp point. Napa guy tells me these plugs are good for 100k miles. I had these plugs in for a good 15k miles and so far, they are still looking super clean. One thing for sure, startups and idling are way better over stock champions.