Let me start by saying AAAARRRRRRRGGHH! OK, 2000 F250 5.4 292,000 miles, no problems until recently. "Betty" starts and runs fine until she gets warm and then she starts to miss randomly. If I make a hard left turn she starts missing worse and more regularly. I brought her to the Mech. about 6k miles ago because she was missing and I went to change the plugs and the brass nuts on a few coils had been over-tightened and spun in their seats. Mech. pried out the offending bolts and epoxied the nuts back in. He reported that there was water sitting on one of the plugs (of course he didn't write down which plug it was), he fixed it and she was fine. He also tested the coils and did a full run-thru. Now same miss is back. I figured the intake is probably cracked and is leaking onto plug causing ground-out. Waited til she started acting up today and started pulling coil wires one at a time looking for the "no difference" offender...couldn't make it out. I did notice that one of the coils was not tightened down all the way but when I pushed it down it was already seated. No visible leaks, no CEL, so I can't get it checked electronically (can I?) Starting to get frustigated. Also the exhaust smells weird. Ideas?


So I pulled the rear passenger side coil because I had a premonition that it was the Perp. I was correct and it was wet. Changed the coil and packed the boot with dielectric smoo. Now I know its a leak and I suspect its the plastic manifold or gasket since I couldn't find any leaky hoses. Anyone have a similar problem, if so, tips?