Door lock problems

[kuds]

I did a bit of searching but couldn't find any good answers.
Here's what my door locks are doing:

1. About 75% of the time, when i lock my doors (in either door), the whole car locks down, but then unlocks. I turn the key again, and then it stays locked. Is this normal?

2. Sometimes, on either door, it's hard to lock the door, like the key turns but with trouble, and only one of the locks goes down, the trunk and the other door stay unlocked.

Is it all from the same problem? Any thoughts on what it is?
The car is a 92 318is.

[Justin e36]

1. each door has a sensor/switch so it knows the door it closed.
one of your sensors is not working properly, so the door unlocks again. attempting to lock it a second time will work.

go ahead, try it. open a door and try the central lock. the doors will unlock. do it again, they'll stay locked.

2. the key turning with trouble could either be a problem with the tumbler, or more likely your key is worn or slightly bent. Your door locks, all hinges, etc. should be oiled up with every inspection 1 and 2. If you haven't done it recently, that's probably the reason you're now having problems.

[kuds]

Originally Posted by Justin e36

1. each door has a sensor/switch so it knows the door it closed.
one of your sensors is not working properly, so the door unlocks again. attempting to lock it a second time will work.

go ahead, try it. open a door and try the central lock. the doors will unlock. do it again, they'll stay locked.

2. the key turning with trouble could either be a problem with the tumbler, or more likely your key is worn or slightly bent. Your door locks, all hinges, etc. should be oiled up with every inspection 1 and 2. If you haven't done it recently, that's probably the reason you're now having problems.

1. So basically the sensors are finished and they think that there's a door that's open? I guess I can pick those up at the dealership, right?

2. I'll try using my 2nd key, see if it still screws up. I haven't done any inspections at the dealership since i've owned the car, so I don't think anything has been oiled up. Should I bother oiling up or do I need to change parts at this point?