Obtained the title to the project Durango today. I went into this knowing that there could be something major wrong with it and based on what I found today there might be.

I replaced cap/wires/spark plugs, and tried a new coil. I still get a random misfire and ****ty running.

This is what I saw when I pulled the #1 plug:



I'm assuming this is oil gunk and there is either a valve issue or excessive blowby. I may end up doing heads on this motor, but the transmission also doesn't shift into 4th, so I may just sell it outright and get rid of it.

 

Wow. Has the plug ever been changed?

IndyD

 

I don't know, and what's funny was, that was the only Champion plug in there. The rest were what looked like NGK Iridium plugs.

 

Do you have the tools to compression test it, if you do that would my advice. It would necessary to see how bad the rings are in that piston, assuming the timing of the engine is still correct.

 

If that was a champion, and the only one, my bet is it is an original. It may have been stuck and they skipped it. Certainly didn't work like that.

 

I'm going to pull the #1 plug again in the morning. I also discovered the negative battery cable was loose when I tried to start it at my son's school open house earlier tonight, and the CEL didn't come on for a good while while it was running crappy. It eventually did start misfiring again, so I'm assuming it's getting oil fouled or there's just something else strange going on.

 

Well blow by would not cause that, because blow by is between the rings and the cylinder walls that end up in the crank case, not backwards into the cylinder head.


It does look like oil foul, but I would change it out for a new one because if it was a fouled plug and in there for a long time it could look like that. Besides, it could be a bad plenum gasket.

It is strange because usually a oil leaking cylinder is the rear sides because the motors usually sit non level. With that said I would do a compression test and replace the plug and see how she runs.

 

Was is soft? I thought it was all hard as in carbon buildup over the years.

 

I replaced all plugs and wires and cap. Could the rotor be causing the misfire? I guess at $5 it'd be worth finding out.

 

In this situation most likely not, but it is a good idea to replace it anyways. Usually replacing the cap and rotor is standard.