02 f150 5.4 160000K. New engine at 100000K.

I just bought this truck and after about 250 miles it started missing. I pulled the code and it was cyl 6. I pulled out the coil and it was filed with unknown liquid. Dried it out, replaced the plug and COP and used dielectric grease. Ran great for about 80 miles and started missing again. I pulled the coil and more liquid ( I think from gasket, maybe coolant) I dried it out replaced the coil, used more dielectric grease and it ran for about 3 miles and started missing again but I pulled the same coil and there was no liquid. Then I found a small hole one of the EGR sensor hoses (small 1/4in black hose). Replaced it but it is still randomly missing with no CEL. It misses when going up a hill and after it heats up and starts to miss more and more the longer it is driven. If I can get it to run ok for about 300 miles I have a guy that worked at ford for 25 years that will fix it the gasket problem and any other. Any ideas to get it to stop missing?

 

Oh me, jham, I hope you get'er fixed good! I have about the same truck, but no problems yet. Only 89,000 miles on mine. Mind me asking why was engine rebuilt at only 100,000 miles? I like mine to go at least 150,000 with no major issues, and they usually do.

 

Fix the leak then replace the bad COP and plug.