Ford Repair: 2002 Ford Explorer 4.0, valve seals, 2 quarts

Question
I seem to be using alot of oil,new motor has 65,000 miles on it& I only run 5/30 synthetic no visible leaks,no smoke,no check engine light.2 quarts to 1000 miles not good!I checked sparkplugs and they get bridged up with a tanish to black carbon deposit.Is this a sign of bad valve seals?If so can I change them with the engine in the truck on this engine? Thanks for any help.

Answer
Unfortunately you or a mechanic will have to be the judge of the extent of the damage. You can tell a lot from the spark plugs. Most parts stores have pictures that should be able to assist you. I do believe that the fact that you have dirty plugs, and extreme oil loss is not a coincidence. An engine rebuild or replacement is probably due. Place a large piece of cardboard under the truck when you park to rule out a leak. With any luck it is a bad gasket, and the dirt on your plugs is unburned fuel.