Author Topic: Passenger Side Door Lock Sticking (Read 2817 times)

DRTE30 · « **on:** January 29, 2012, 09:30:02 PM »

Long time lurker; first time poster.

I have a 1991 318is and am having intermittent issues with the passenger side door lock sticking. There are three different scenarios that yield slightly different results in how the passenger door lock will react.

1) If I lock the car using the driver side door, I cannot unlock the car from the passenger side door. The key will simply not turn within the lock mechanism.

2) If I lock the car using the trunk lock, I cannot unlock the car from the passenger side door. The key will simply not turn within the lock mechanism.

3) If I lock the car using the passenger side lock, I CAN unlock the car from the passenger side door, the driver side door and the trunk lock.

I found that Pelican sells a lock rebuild kit, and in fact, there is also a write up on this website about it. However, I am unsure what needs to be done to the passenger door, and as stupid as this question is, I wonder if the same rebuild kit is universal to the passenger lock to rebuild it? Here is the part number for those whom are curious as to what I am referring to: 51-21-9-061-343-M9

Conversely, searching online as well as other forums has yielded plenty of information regarding the rebuild/repair/replacement of the driver side door lock, but nothing in regard to a sticky/malfunctioning passenger door lock.

If anyone has any first-hand knowledge of this, please chime in. This has plagued my little car since taking ownership and I would like to repair it tentatively soon. Thank you.

colin86325 · « **Reply #1 on:** January 30, 2012, 09:15:03 AM »

The double-lock system is enagaged when the driver's lock or the trunk lock is rotated 90 degrees (vs 45 degrees for normal locking).

When the double-lock is enagaged, the car can be unlocked only from the driver's door or the trunk.

When the car is locked from the passenger side, the double-lock is not activated and the car can be unlocked from any door.

I just rebuilt my driver's lock and the kit contains extra parts. You can use the kit to rebuild the passenger lock. There might be a passenger-specific kit that contains fewer pieces (and could be cheaper for this reason) but I don't know if it exists.

DRTE30 · « **Reply #2 on:** January 31, 2012, 11:52:11 PM »

Cool. Interesting. Thanks for the reply. So it seems that all systems are normal with my car with what you say, and it simply comes down to me not being familiar with the locking system and how it functions - which is totally the case. I appreciate the clarification. Also, I have checked with all the major distributors in regard to a passenger lock rebuild kit, and I cannot find anything. It's quite possible I overlooked it though.

Out of curiosity, what symptom(s) provoked you into rebuilding your driver side lock?

colin86325 · « **Reply #3 on:** February 01, 2012, 09:53:58 AM »

My lock was just not turning smoothly. It would bind up when I attempted to lock the car. Also, the other locks were not being triggered when I locked the driver's door and I had to use the trunk lock instead.
When i removed the lock I could see where several bits of metal had broken off the rear of the lock.

I think 51 21 9 556 313 might be the rebuild kit for the passenger side lock, but no promises!

http://bmwfans.info/parts/catalog/E30/2-doors/USA/318is-M42/browse/bodywork/door_handle_front_lock_key/

DesktopDave · « **Reply #4 on:** February 01, 2012, 01:10:04 PM »

My passenger lock is just plain sticky, especially when it's really cold and water freezes up in the lock cylinder. I just live with it...but I found that graphite dry lube does a decent job with the lock. Don't try WD40 or other penetrating lubes, they work temporarily but then make things far worse as they plug up the cylinder, accumulate water then encourage corrosion.

DRTE30 · « **Reply #5 on:** February 03, 2012, 03:50:16 AM »

Thank you for the link to that potential lock rebuild kit. Though again, if the "symptoms" I'm experiencing are in fact a standard operating system, there is no need to fix anything that isn't broken. My driver side lock could use a freshening up so I'll look into getting the repair kit for that from Pelican. I may, for fun, swing by the stealership and ask them about a passenger side repair kit, just to put it to rest and see what they say for future reference.

I stay away from penetrating lubes strictly for those reasons. Thanks for the suggestions however. It never hurts.