How are 2003 Ford Expedition spark plugs numbered?

We need to change the spark plug %26amp; coil wire on #3. Problem is - how do we know which is the # 3?? A friend changed what he thought was the number 3 - but the numbering must have been misinterpreted, because it wasn't the 3. Changing spark plugs is like our monthly maintenance on this beast %26amp; I hope once this one gets done it will settle down...thanksHow are 2003 Ford Expedition spark plugs numbered?
Scullycj is correct about the way the cylinders are numbered. Cylinder #3 is the 3rd cylinder from the front on the passenger side. Or interpreted another way, the 2nd cylinder on the passenger side from the firewall. If changing spark plugs seems like monthly maintenance, you obviously have other issues causing the miss. One last, but very noteworthy to mention tip. Use ONLY Ford/Motorcraft spark plugs and other electrical parts in order to avoid headaches. Doing this job more than once is probably no fun as you already know. Hope this helps.How are 2003 Ford Expedition spark plugs numbered?
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Passenger side starting at the front going backward. 1-2-3-4 Drivers side starting at front and going back. 5-6-7-8
If it is a straight 6, the front plug is #1 and the rear is #6. If it is a v8, the plus number 1-4 on the right side and 5-8 on the left side. The cylinder number should be cast on the intake runner to that cylinder. At least they used to do that.