w114 Driver Door Will Not Lock

[Skippy]

The other three work fine. The driver door will not lock from either the inside or with the key. The key won't turn, and the plunger on the inside will not go all the way down. Ideas?

Incidently, I haven't been able to get the trunk to lock, but I'm not as concerned about that at the moment.

[JiveTurkey]

Have you squirted some liquid graphite in there? Might want to give that a shot since thats a simple way to start off. Coincedentally thats about the limit of my experiance dealing with door locks gone rebel, other than chasing vacuum leaks.

[meltedpanda]

pull off the door panel, pretty basic mechanisms, perhaps yours has malfunctioned. Door panel easy to remove, there is a small screw behind the door handle, that most miss when taking apart

[250 Coupe]

The drivers door won't lock unless it's fully latched. Either it's not really latched or the linkage that tell the lock it's latched has gone South.

As meltedpanda says, you'll have to take the door panel off and play with it to get a handle on which does what.

Michael

[Pooka]

Are you are running into a situation where the lock on the drivers door will not lock when you turn the key or when you push down the button on the door? (The answer here is Yes, so we go on to question 2)

Does the button, when pushed down, feel 'squishy' or 'spongy', like it wants to lock but something is pushing it up from below like a big spring?

If the answer to this question is Yes then you likely have a vaccume problem or it could be something as simple as what I call being 'out of time' on your locks.

Sit in the car, start it and let it run for a moment to bulld up some vac reserve. While the car is running slowly push down the button on the drivers door and see if all the locks drop. Wait a moment and unlock the drivers door and see if the other door locks lift.

This may not be your problem, but it is free to try and only takes a moment. The best part is many times it solves the problem you describe!

[meltedpanda]

I don't think he has vacuum actuated locks???

[Skippy]

I don't know if it does or not. It didn't come with an owner's manual. I've been meaning to take that driver's door card off in order to replace the side mirror, but I've been leery of doing so for fear of the nearly 40 year old cardboard falling apart. I guess I may have to go ahead and do it now.

I will start with Pooka's idea this afternoon.

[Skippy]

I tried locking it from the inside with the engine running. No joy. Then I opened the door and moved the latch to fully latched with my finger. I was able to lock it. Since then, I've been able to lock it from the inside. I bought some graphite, but it's dark now. I'll try that tomorrow.

[Pooka]

Skippy, et al....

Sorry. I just assumed you had vac doors since most US delivery 114's seemed to have them. At least all the ones I ever owned did.

It was sort of a mandatory option thing. Maybe just all the Mercedes in the Southwest Delivery region (Dallas and Houston) had them.

Like sunroofs. Optional, but good luck trying to find a car at a dealership in the SW region in the 70's and 80's without one.

[Skippy]

That's interesting. When I bought the car, it had a University of Nevada Sticker above a University of Texas sticker, and 1992 parking stickers from Lawrence Berkely Laboratory. It does not have a sunroof. I don't know where it was sold originally.

[250 Coupe]

2 of my 114's, a '69 250/8 and a '71 250C, did not have vacuum locks. The '76 280C did.

Even if yours does have vacuum locks, the drivers door does not have an actuator but does have the valve that controls the other locks. The spongy springy resistance comes from an actuator that is resisting the manual lock. The valve in the drivers door usually leaks rather than sticks so I would suspect the "don't lock until it's latched" feature first.

Make sure that the cone on the door is shiny clean and that the rubber lined socket on the jamb is also clean. They can keep the door from closing fully and can make it nearly impossible to open.

Michael

[Skippy]

My immediate concern was getting the thing locked before I had to leave for a trip. One of the neighbor kids has a habit of checking car doors and "exploring" any that he finds open. I'm about 500 miles from the car right now, and troubleshooting can resume when I get back. Thanks for all the input.