From digest.v4.n808 Fri Jul 5 06:35:54 1996
From: prreitz_at_amp.com (Paul R. Reitz)
Date: Fri, 5 Jul 1996 07:27:31 -0400
Subject: <E30> Double lock can work

To follow up yesterday's post, with a sheepish grin and something of a red face (but not without some redeeming value, read on,) I want to correct what I said about the double locks not working by design on the E30.

Note, all, this applies to E30s only.

>How come I am not able to deadbolt my driver's side door lock on my 85
>318i?

San Do's question about *exactly* the same symptoms, which by coincidence crossed in the e-mail, somewhat justifies the previous post. This is, apparently, a common problem. Thanks to REB's observation that he has seen it work on several E30's, and having carefully analyed the remainder of the system to know well that it could not double-lock any other way, it finally dawned on me how the driver's door is supposed to "double-lock". What follows is only a tentative conclusion (engineers always hedge.)

San Do, I think our mutual problem is a faulty key lock cylinder. The only way the driver's door can "double-lock" (actually, *jam* is a better term for the driver's door) is for the key lock lever to remain extended in the locked position after having been rotated to the 90 degree position. That is, the key lock lever is *apparently* supposed to act like a snap switch. When the key is rotated past 45 degrees, a spring attached to the lever not only allows the lock cylinder can continue its rotation (even though the operating lever on the door latch cannot move any farther), it also (apparently) is supposed to snap the lever into a mode where it will remain in this position even after the key is rotated back to the upright position and removed. This would jam the mechanical door latch in the locked position. Then, *apparently*, when the key is rotated CCW to unlock the car, the snap switch snaps the lever back to the unlocked postion, unlocking the the door and allowing the other components to signal the other doors to unlock.

I know that the lock cylinder on our car is not doing this, and I think it's my fault! About a year ago I R&R'd the lock to fix up some cracked paint around the lock. Observing that the lever did not operate smoothly, I lubed it! Wrong!

Now I've got to dig in there again to get the lock out and hope that a good cleaning will restore its snap feature.

BTW, the easy way to get to the lock after removing the door panel is to bite the bullet and remove the power window motor. This is actally fairly easy. It's also not too difficult to then remove the window rear track guide (1 bolt at the bottom of the door, then pull it away toward the front. This gives plenty of space to work inside the door.

Hope this helps, San Do, and regrets to all others who I may have worried. However, it wouldn't hurt you to check to make sure your driver's door is double-locking!

• -Paul Reitz BMW CCA #1167