Dear Ole Mechanic;
I have a key problem with my 2002 Ford Explorer. Unlocking the drivers door with the key has gotten progressively harder, and now it is at the point where I am afraid that I am going to break the key off in the lock. I've started using the key to unlock the passenger door and then using the power lock/unlock button to unlock the drivers door. Even when using the power button, I need to hit it two or three times to get the drivers door to unlock. I am considering getting some penetrating oil and spraying it into the drivers door key hole. Would that help, or is there something else that I should do?
Visiting for the Holidays
Until I saw that you are visiting, I was going to ask why you were bothering to lock the doors? It just makes it harder to get to the ignition key, which is usually left in the ignition switch here in my town. You could just move here and then leave the doors unlocked!
OK, now to your real problem. First, I cannot recommend putting penetrating oil in the key hole. While it might loosen things up temporarily, the remaining oily residue will collect dust, dirt, and other crap in the close-fitting areas of the lock tumbler and make things worse in the long run. What I would recommend is putting powdered graphite in the key hole and on the key. Yes, graphite is messy, but it does lubricate without leaving a residue to attract dirt. If it has already been oiled and gummed up, use a non-oily liquid like alcohol to flush things out as best you can, and then follow that with powdered graphite.
While lubricating the key with graphite may help your problem, I don't think that the key tumbler is your problem. Key tumblers do not turn when you use the power lock/unlock button. The actual door locking mechanism can be activated either by the key or by the electrical-solenoid. Since the passenger door button must be hit two or three times, that tells me that there is a linkage or locking mechanism problem--not a key or electrical-solenoid problem. This type of problem is inside the door, and to get to most of it, the interior door trim-panel must be removed. Since the interior trim-panel usually has a number of electrical and electronic controls and wires attached to it, I cannot recommend that you try to remove the panel. The reason for that recommendation is that the electronic controls and wiring lead to one or more of the on-board computers built into your Explorer. Computers are internally very sensitive to electrical surges. The human body normally has a 30 to 50 volt static electrical charge built up due to movement inside of our clothing, and should you touch the wrong connector, that 30 to 50 volts can travel through the wire to the inside of the computer,where things are designed for no more than 12 volts. Ouch! You just fried the computer and upped your repair bill!
OK, what can you do? You can take that penetrating oil that you were talking about earlier and spray the latching mechanism liberally. I am talking about the part at the back end of the door--the part that latches to the door post at the back of the door. Be sure to have a rag ready to wipe up the excess that runs out. Also, hope that some oilruns inside the door and onto the internal parts where it needs to be. Beyond that, it is time for a visit to your favorite mechanic or your favorite Ford dealership.
Of course you could always move to a small town away from any interstate highway where people don’t bother locking their car doors and may even leave the vehicle running while they are in the Post Office.
Herr Professor Nuzanbolts