Sorry for this OT post. I'm just trying to expand my general automotive knowledge. The car is a 99 Lincoln Town Car with a bone stock 4.6 modular V8. It's got 184k miles, I bought it new, and I have always performed my own maintenance and kept the car in tip-top condition. For the record, it's been an amazingly reliable car. If anyone is looking for a comfortable late model family cruizer, give one of these a shot. But at any rate, Two days ago, it developed a slight miss. I pluged the code reader into it, and it came back as a miss in cylinder #5, indicating a dead plug or a bad coil... Hmmm... I just replaced the plugs with the last oil change, and replaced all the coils about a year ago. [lifetime warranty]... Ok, no big deal. So I pull the covers and intake plumbing off, and go to pull the #5 coil, when I discover it was loose... Apparently I had forgotten to "torque" it down when I installed the plugs, and the vibration had caused it to back out. Tightened it down, checked all the others, they were good, and the miss went away. It's run great for the last two days. Then this morning, the miss returns. Only this time, it gets worse. Over the course of about an hours worth of driving, it goes from a slight intermitent miss, to a full boogie dead cylinder. The car has a vibration, and the dead cylinder can clearly be heard in the exhaust note. What's more [and this is important], you can hear a static-popping in the radio when the dead cylinder tries to fire. I got home a little while ago, and pluged the code reader into it... Once again, it said that #5 was missing. I stuck my hand down there and it's still tight,,, hasn't backed out again. So it's obvious that either the plug or the coil has crapped out totally. I'm going to replace them both. The coil being under warranty means the total repair will cost me $3 for a plug... No big deal. My question for you late model Ford gurus is this... Do you think the plug was fried because the coil wasn't making full contact, or do you think the coil was burnt because it was arking while it was loose??? I suspect there's a powerfull hint in the popping comming thru the stereo speakers, but I'm not smart enough about late model stuff to know what that means Like I said in the beginning of this post, I'm just trying to expand my general automotive knowledge, and would be interested in what the experts think of this situation Thanks guys
Loose connections to the plug will toast a coil / coil pack. Had a couple of the triple ones toast themselves on my 6 cylinder Fords. Given an open circuit , the coil voltage goes sky high and arcs the windings.Expensive lesson on the 6-cyl cars! HTH Jorge
Always replace the rubber boots and springs when doing plugs on these. Also, a coolant leak willl fill up the plug area and cause this. There's lots of coolant issues with the plastic intake, especially near the heater hose fitting in the back.
Just went through this with my 2000 Mercury Marquis......................Change the boots and the springs!!!!!! I did them in conjunction with the plugs, and did it as soon as I "felt" a glitch........... It never "latched" a code.
The new coil should have come with a boot already on it... Most problems i've fixed for the intake is the plastic water crossover cracking right behind the alt, the new intakes have a metal water crossover
Yea, the new one came with new boots. Never had a problem with the intake, or anything else on the car. I'v replaced one alternator, one fuel pump, coils, P/W motor twice, along with one P/W switch, T/C [under warranty @ 23k miles] and rebuilt the front suspension twice... Other than that, just regular maintenance stuff, tires, brakes, battery, fluids, filters, etc. The local used car lot has one of these with 161k miles right now for $2750. If I had an actual need for another car [yea, like another hole in my head ] I would have already bought it. If anyone is looking for a good car, IMHO, you'd do well to give one of these a closer look.
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