So the other day on my way to work I am sittin at a light and hear a pop. When I took off I could hear it and I thought oh great. Well I looked and figured that I had blown out a exhaust manifold gasket. Well I got some money together and ordered a full mac exhaust. Headers pro chamber and cat back. Figured do it all at once. Well since I need to retune it after that I went ahead and got my jlt intake. I went to put the intake on today and when I removed my stock one I noticed oil on the valve cover. I am like sh*t this can't be good. I removed my coil cover and find that the second one is in pieces. I then look at the spark plug and notice that it isn't sittin right. I pull it out and look at the threads and look at the hole in the and and it blew out. I ordered the kit from time sert and I am goin to fix it and get a new coil. I talked to a friend of mine and he said that it will be stronger than stock. Anybody else seen this happen?

 

I didnt blow out a plug like you did. But I did have LOTS of oil in my numberone whole . I looked at the boot of the plug and it wasnt even touching . I was reading at a MARK VIII site that this is a common problem and all that is need is to replace the parts. I also had another member on here said to replace the cover gasket , but I have not done this as of yet .. Tell me what you do and how it turns out ...OHH by the way I have a 98 MARK VIII....

 

That is really common in the 5.4l trucks... usually around 120k or so, and usually only if they have never been changed... don't know why that has any relevance, but if you change 'em they don't seem to do it...???