Hi.
You mean: "without opening the door itself"?
I have fixed almost the same problem on my w140, on the front passenger's door: sometimes it would open from outside, sometimes not... but would always open from inside, and no locking problem on top of the handle issue.

I would say that without opening the door, that's not possible. Removing the panel to get access to the whole (complex) system requires to open the door, and first, unsrcrew the small screw maintaining the plastic cover of the lock.

On this picture, you will see the small square hard plastic part on the far left, just covering the lock.

Then, with the appropriate tool, separate the panel from the door, which seems impossible if it remains close to the door seal, without any room for manoeuvre.

Take an example from the opposite door on your w140, you may see all the steps to go through before you can remove the panel.

As a conclusion, on my w140 the whole lock was poisoned by a small part of plastic coming from inner rubbers that went through the locking system, blocking or restricting the opening kinematic of the lock.

So, even from inside can't you open the door?

Jean-Louis

 

Ohhh Dan Ohh Dan...

I have the same problem, and so does a customer of mine...

I have exhausted the vacuum unlock mechanism, and that is not it....

I did find a DIY of some kind onto the approach to do this. Take a look:

http://www.benzworld.org/forums/w140-s-class/1587585-my-95-s320-w140-ds-rear.html

http://www.benzworld.org/forums/w140-s-class/1564319-w140-ds-rear-door-stuck.html

Martin

 

According to my brief experience, the problem is not electric or pneumatic, but a mecanical one.
If the door does not open, it is because the classic locking system does not operate properly.
Apart from removing the door panel, and then, inspecting and fixing the locks and handle linkages, I see no other possibility.

One thing: have you tried with a helper that would pull the external handle wide opened, to open the door from the inside? Pushing strongly? I guess if the handle can move the lock enough, then opening from the inside could help?

Jean-Louis

 

No the door wouldn't open from either the inside of the outside. The only way I think I can get the door open is to remove the two screws that hold the striker/latching plate that is fixed to the body. But the only way to get to them is from either the trunk or fender well. If I can cut those screws off flush them the door and the body latching plate will open...... Hopefully. Unless someone else has a better idea.
Dan Mauch

 

On one rear door (123) it was the actuating rod (14" long approx) that was no longer attached to the door button that visually shows the door open or closed. Unless I can kick the door open I am ready to use a circle saw to cut a hole where I can "pull the rod" and open the door---look for a new door panel in the junk yard. ??? Gary

 

See this. Not a W140, but another S class car. Crude, but effective.

Sent from my Nexus 5 using Tapatalk

 

Dan ,I owe you one .
You might have access to the connecting rods by removing the burlwood trim piece in front of the door handle , behind it you will find plastic then a small hole , maybe just enough to pull the lucky rod .
If you then get the door open .
At the rear door ,there is a hidden Latch that only becomes visible when you pull on the Door Handles , check the latch with the white Striped arrow (pointing left) , as you pull the handle it should poke out a little as you see in the pic , if not feel it with your hand .
The connecting rod comes of easy & could have dislodged itself . Finding this one drove me nuts when I fixed the rear window regulator on mine , door simply wont open without that bar connected .

If you like to check the Door Handle operation without removing the trim 1st ,Remove the Nut/Screw on the outer edge of the door , hidden behind a small black round clip covering ,follow the level of the door handle ,then pull the handle on that side out slowly ,on the other side of the handle you have sort of a hook ,you can see if the connecting rod is attached from there .

Just took A picture for you as I know this hole is not easy to find or see , hidden completely behind the rubber seal . It's a HEX nut type screw . On the bottom of the pics you find a PDF door trim removal file if you never done this before.:thumbsup:

 

Same proposal as in the video: a helper inside the car pushing strongly, while you pull the handle opened from outside.
I am almost sure it could be the only way, as long as the lock is not engaged.

Otherwise, if you can spray some penetrating oil through the opened window lips towards the locking system, just to ease its kinematic.

Jean-Louis

 

This is how the trim looks from behind , see the big hole behind the burlwood piece in front of the handle , it's directly underneath the door interior handle , if your arm fits into it if everything else fails ,you get that door open thru there .
Hope this helps you you out more .:thumbsup:

 

Hope you say true, that could be a very clever way.
Anyway, I doubt that males like us could have one arm go through the hole and operate the lock at the other end of the door. On the way, there are two big rails guiding the glass, and very few place left indeed.
There must a trick in the explanation I did not get, so I will wait for Dan's report, but so far I find that solution very clever.

Jean-Louis

 

Well it's a lot more difficult than I thought. I called my MB dealer. They told me that they sometimes have to drill a hole in the trim to get to the linkage near the lock. Since I have sourced a replacement door liner I went ahead and using a hole saw cut a hole where the linkage bells crank for the central unlocking system connects to the door latch mechanism. I was disappointed to find that it was still connected to the nylon clip for the lock linkage. The hole was large enough that I can also see that the door handle is connected to the latching mechanism. When the door handle is operated with the locking mechanism in the unlock position the door still doesn't open.

Here is how the door mechanism works. When the door is closed the harden lock ring engages the striker plate and rolls by cam action the lock ring to the fully locked position. If the door central locking system or the button in pushed down the linkage is pulled towards the front of the car and by a series of levers and cam action moves the locking link so that if either the door or the inside handle is actuated then the door remains in the lock position. When either the button is manually raised or the central locking system is actuated then the operating linage at the door lock moves to the unlock position,. Then if either the inside or outside door handle is operated then a lever lifts the locking pawl and then torsion spring on the harden lock ring rotates to the unlock position.

But that is my problem. Apparently, the torsion spring is either broke or disconnected or the hardened lock ring is frozen on its pivot pin.Since I can't get the door liner out without opening the door and I can remove the backseat backrest because the door is closed.... I'm screwed!.I will try spraying some wd40 into as much of the locking mechanism as possible and hope that it frees up either the torsion spring or the locking ring. Even if I could remove the liner or the backrest I still don't think I can get access to the locking ring.

Dan Mauch

 

Hi, I suppose the issue is a difficult one, so sorry to insist, but, did you try the "push/pull" of the door procedure?
Someone inside, someone outside, the one outside maintaining the handle opened and pulling strongly, the one inside maintaining the trigger opened and pushing strongly, both applying a gradual strength, no brutal action on it?

Jean-Louis

 

Here's the technique Jean-Louis is describing.

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Thanks Jean, Yes my son and I tried various push pull methods bone of them will work. The video has a totally different lock mechanism than the 97 s320.
I found on Amazon a <$20 endoscope that might let me see the actual locking ring and the torsion spring.... I hope.
In the meantime I will try spraying wd40 into the lock from the hole I cut in the trim panel.
As a last resort I may have to cut the outer door skin and remove the lock that way. I can replace the whole door for about $300.
Dan Mauch

 

Ok, that was just to make sure the basic solution was not giving any improvement. Once the basic solution is over, complex ones can be looked at. Of course the door mecanism is not the same compared to the video, but I insisted because I had "almost" the same issue on the front passenger's door, that usually refused to open from the outside, but never did from the inside. Then, and because I fixed that issue for good by removing the whole system from the door, I realized that, except if the mecanism is locked or totally broken, it does allow to open the door... but sometimes not from the outside.

Two more things: an endoscope is a very good idea, you can find ones at low price that plug on your cell phone or pad, with a dedicated software you download. That can help identiying where the problem is, but it will not fix it.

Then, 300USD is not so much on a w140 if it can fix the problem. But before spending that money out, could you have some more clues? For instance, before replying to you, I went to have a look at the car, jumped on the rear seat, closed the door, and wondered: "can I remove the factory door frame seal with the door closed?". It seems it can be removed quite easily, which becomes easier if you are able to remove the rear seat and the rear seatback (that is another matter). Even though the seat remains, I am now almost sure you after the seal is out, you can remove the door panel. The difficulty remains on the small plastic finishing cover, that you may be forced to destroy in order to free the door panel.

On the first picture of the front door, you see the location of the plastic cover I am talking about, at the far right of the door. Rear door has the same system (well, check on your car, but should be).
As long as the cover is out, the door panel can be removed with patience but without damaging anything I guess. After that, you will find the locking system (I insist, it is a system, complex) (second picture attached). But, as I saw, most probably you will have to remove the cover by breaking it (do not know how).

Jean-Louis

 

Can you get to the back side of the door post where the body side of the latch attaches? I don't have a sedan, so I can't look. You might have to remove a fender liner. You might be able to cut through the nut plates and bolts with a cut off wheel to release the body side of the latch. Would be less destructive than what you described, and fairly easy to repair.
Also use PB Blaster instead of WD40. It is a better penetrant.
You might also try a heat gun it you can get it close enough to the latch assembly. Might expand things enough to allow release or help open things up to get penetrant in.
Ken at Mercedessource or Victor at repairyormercedes.com might have some ideas. I'd try contacting them.

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Thanks. I had already thought about that. I can remove the back seat but cannot get to the backrest bolt above the door panel because the door panel wouldn't let me remove the trim piece covering it. I did remove the passenger side trim but it doesn't look like there is a way to get to the striker plate bolts. I also look in trunk and the bolts are not there. I also removed the wheel well liner and no luck there.
Dan Mauch

 

May I suggest several answers to your remarks?

1. I do not know precisely what kind of back rest your car is equipped with, or whether there is a significant change in the design of the back rest between mileages, but I can tell you IIRC I can remove the back rest without removing the C-pillar cover, and then properly remove the factory seal. I did a heavy DIY restoration of the rear leathers/safety belts/C-pillars three years ago, and what you have to do is:
- a. to take the head rests off,
- b. then the hat tray off,
- c. then you access to the upper back rests bolts, unscrew
- d. then remove the back rest
- e. then access to the lower screw of the C-pillar cover, unscrew
- f. then remove the C-pillar cover
(see pictures below)

2. I am almost convinced there is no other way to open the door without damaging a lot of items. Just imagine one could remove the wheel well liner and drill the lock gash from there? That would not be a safe system at all if that could be so easy! Getting an access via the trunk sounds a good idea anyway.

Jean-Louis

 

Here are some pictures that say a lot about the problem. I received this lock and figured out how it works. MB wants $900 for one. I bought it off ebay for $25
The first picture shows the unlocked position. The second picture shows the locked position. The third picture shows the lever and pawl that release the locked torsion spring and unlocks the door. The rivet below the hardened steel cam acting locking ring is the axel or pivot point which could be corroded or the torsion spring came loose or broke.
So even with the pawl releasing the locking ring it doesn't unlock on my door if either the lockring is frozen to the pivot point or the spring is defective.

Dan Mauch

 

I finally got the backrest out. Using brute force and some of those plastic wedge tools I was able to pry up the trim cover that hides the upper backrest bolt. Surprisingly, I did not damage it. But I found a replacement if I did damage it. Then I was able to pry out and remove the door liner seal. I have located what I am pretty sure is the striker nut plate or at least I think I have. There is a backward c slot above the cable and tubing guide. Inside that slot is the striker nut plate. The photo shows only the top of the nut plate. Somehow I need to cut the sheet metal slot down further to access the whole nut plate so I can figure out how to cut the screws off from this new longer slot unless others have a better idea.
I will receive the endoscope tomorrow so I can see if it is worth trying. with the backrest remove there still isn't any access to the locking mechanism.

Dan Mauch

 

Seems to go ahead in the right direction.
I do not get whether you have been able to remove the door panel or not.
Then, I am not sure about what the picture shows.
What I understand is that you want to cut the lock strike from the inside, right?
Take a lok at my picture #3, you will see the strike, and its location, that is far behind the wheelbase door welding. Seems difficult to see from the inside, so even more difficult to cut.

Once the panel is off, you will see the mecanism, and most probably be able to remove it from the door frame.
There is another possibility, is that when the panel is removed, you get access to the door hinges that guide the door on the wheelbase B-pillar. Most probably, with a helper and a good system that can maintain the door, you may unscrew the higes out from the wheelbase, and have the door slightly opening from the B-pillar. That may allow to get some room for manoeuvre and apply a strong strengh by moving the door itself, with low angle on each direction, on the locking mecanism itself, which may unlock it or at least ease its kinematic if something is stuck inside.

But these two possibilities need first that the panel is removed.

Jean-Louis

 

OK folks, I skimmed this thread so forgive me if I'm repeating anything. I had this problem (sort of) previously as well, when I first got the car. The driver's side rear wouldn't unlock. I couldn't get the door panel off (or at least it was too difficult with the door shut). What eventually worked for me is unfortunate, because it leaves its mark on the door panel and the lock...indicator....popup thing on the panel.

My issue was, the liner had melted around the lock's rod. Along the entire length. There was not nearly enough force being produced by the vacuum to overcome this. So I used tools that gave me a lot of leverage on the rod (from the popup thing) to get it up enough to open the door, then took off the panel and cut out the liner around the rod.

Unfortunately, this left about an inch and a half scar around the popup, and the popup itself was pretty scarred as well. But I couldn't think of another way to get it done, and I'll take a blemish over an inoperable door.

 

I am awaiting the endoscope to see inside the slot. As you can see I butchered the door panel to get to the lock mechanism. I am fairly convinced that on my S320 that the door lock mechanism is inaccessible even if I got the door panel off. With the openings that I made I can see that the door lock mechanism is covered by the steel structure. The slot adjacent to the door is where I am pretty sure that the striker plate retainer is inside. The fiber optic endoscope will answer the question.
Dan Mauch

 

... I am fairly convinced that on my S320 that the door lock mechanism is inaccessible even if I got the door panel off...
Dan Mauch

How do you know?
From your picture, I would say the locking mecanism is just below the wood trim that is still safe on the door panel, I am almost sure the screw that is showing is one of the ones maintaining the lock on the door frame.

Then, as the door panel is already in such a desperate situation, there is nothing that prevents you from removing it, even though you may have to cut all the plastic clips all around the panel's periphery. Pay attention to all the hidden items behind the panel such as wires, speakers, ... Most probably when the clips are cut and the main screw is unscrewed (the one keeping the door handle), the door panel will move easily from bottom to top, out from the glass lip of the door

Anyway, if you choose patience and refine your diag with the help of the endoscope, we will wait after your report.

Jean-Louis

 

Thanks for the comment however the linkage rods are all moving freely and I can see that the central locking system rod and the inside door handle rod are connected and can feel that operating inside the lock mechanism.
Dan Mauch

 

Dan and Jean-Louis,

Thank you for your work and update. This has not been priority for me yet, but my passenger rear door is my problem, and I do not want to cut yet until i find a brown door panel.

Dan I'm wondering when you get the scope camera that maybe a coat hanger could be used to pull on some part of the latch from the bottom to release it.

Martin

 

While waiting for the scope to arrive I will spray wd40 into each doors locking ring. When searching ebay for a replacement door lock assembly I noticed that many were corroded. So if you live in a humid or rainy part of the country spraying the lock through the locking ring opening should be part of your regualar maintenance..
Dan Mauch

 

Ouch! Yes, for sure, that's damaged.
With the picture I sent, you can understand there is no access to the strike from the inside of the car.
I remain convinced you can remove the door panel once the seal if off, and the seats removed.

Jean-Louis

 

I got the endoscope and it was somewhat helpful. The scope could only go in so far and I can see a partial amount of the mechanism but not at the locking ring. Nothing looked disconnected.
The locking mechanism isn't visible because there is a metal plate between the lock and the door panel. In fact there is a screw in this plate that is one of the three screws that hold the locking mechanism in place.
So removing the door panel will do no good whatsoever on my s320.
Now I'm on plan B. The slot that I previously showed is where the striker plate is secured to the body by a retaining nut plate. These screws were somewhat covered by another metal plate that apparently is used to position the nut plate. Using a pneumatic saw I cut the slot down further than in the picture. I can finally see the two screw threads that hold the striker in place. They look like about 6MM screws. About 6mm of the thread shows beyond the nut plate.
Now comes my options.
1. try to install two nuts on each screw. One as a jam nut and try to unscrew the fastener just enough on both screws so that I can saw the screws off right at the car body.
2.There is not enough room in the slot to drill the two screws out so I would have to cut the screws off and then using a die gringer gouge out the screws from the nut plate.

Any other suggestions?

Dan Mauch