P0304: spark plugs pulled, opionions needed

Saturday night my truck threw a P0304 out of the blue. I was able to limp it home and park it until today. I had hopes that it would clear up today, but sadly it ran just as bad if not worse than on Saturday. I pulled the plugs to do a compression test tomorrow, and I noticed two things.

1) I apparently have a valve cover gasket leak on the drive side because there is a little bit of oil on all of the plug wire boots (more so at the very top)

2) the #4 spark plug obviously does not match the other plugs. Does this look like it would be fouled? There was a tiny bit of fluid on the electrodes, but I couldn't tell if it was wasted gas or oil. When I have had misfiring trouble before, I don't recall the plug looking like this, nor did the truck run as terrible as it is now. Also, on the #4 boot there is some traces of white, if that is of any concern or indication of what might be wrong?

#3 and lastly, i noticed the base of the plugs on the drivers side (2,4&6) is more brown compared to that of the drivers side (1,3&5)

Tomorrow I plan to do a compression test and see if there is spark to the plug. Just wanted to see what opinions might be because as of right now I am assuming worst case scenario, another head job.

 

Just my opinion here. Looks like bad wire and or boot connection. Just looks like that one wasn't firing right. Some high voltage leak on the boot. Otherwise all looks about normal. check the resistance of that one. Back in the day I somehow remember 1k ohms/foot. of wire length.

 

Thanks for your input! I'll put that on the todo list for tomorrow!

 

Replace wires

 

Agreed with the others. I had high voltage leaking through those long boots and throwing P030x codes and I didn't think to change the wires before paying a shop to diagnose and charge me >$100 to replace $25 wires.

 

This is starting to make me feel much better. I think I may have an old set of wires just to test the theory before buying any. I hope this will be the case!

 

Yep I had a set of really good looking wires. Still developed a “leak” and shorted. Very very subtle mis

 

I haven’t driven the truck much this week, but after a change of plugs and wires, the truck is running much better. It still concerns my that the #4 plug had apparently fouled, but hopefully there is not a underlying issue to the cause. Time will tell I suppose.