Where are the spark plugs on a 1999 Ford Expedition?

Answer 1

in the cylinder head.... LOL Just kidding a bit... The engines use what is called COP type ignition, or Coil On Plug. That means it does not have a distributor and plug wires like you are probably used to... each cylinder has its own ignition coil. If you can look at the injectors, you will see something about 1.5 inches around with a small bolt holding it in place, and a small wiring harness attached to it. These are the coils. The bolt has a 7 or 8 mm head on it. Remove the bolt and wire plug, and the coil will pull up and off of the spark plug. Depending on which cylinder you look at, it will be difficult to actually see the spark plug, but trust me it is down there about 4 inches deep into the head. They have a 5/8 head, and you will need about 1 3 inch extension for your ratchet to remove the plug. Be sure that your spark plug socket has the little rubber insert in there to. If you are going to replace them, a little tip for you.... lube the ceramic boot of the plug with dilectric grease before you insert it into the spark plug socket. This will keep the rubber piece from stickin to the plug after you install it. Also DO NOT OVER TIGHTEN THE PLUG !!!!! You will F!#$% up your head and the repair is VERY expensive to fix. You can actually rip the threads right out of the head if you over tighten them. It is a bit of a pain to get all of them, but not too bad. I would plan a good 3 or 4 hours the first time you do it. On the passenger side, the back two are tough, but if you take off the brackets where the battery wires connect to (4 - 8mm bolts) and slide the two harneses off of the brackets, you can do it. Just push the heater hoses out of the way