My '84 300D turbo has just developed a problem that I haven't exactly seen addressed in this forum (I'm new here, but I think I've done a pretty thorough search). Attempting to start the car, when I turn the key the tumbler turns, but the ignition switch doesn't seem to be moving to position 1 or 2. I can turn the key 360 degrees (or probably more) in either direction with nothing happening except the buzzer sounding and the steering lock releasing. At this point I haven't done anything other than removing the kick panel so that I can see the back of the switch.

Does anyone have an idea what's going on here? I feel pretty lost.

Also, even if I can't get the switch to work, I am hoping to hotwire, or start the car in some other way to get it back to my house (it's presently in a friend's driveway blocking access to her garage). I'm not clear on how to hotwire it, but if I do get it started in some unorthodox way, will the emergency cutoff shut it down?

Thanks in advance for any help that can be offered, and kudos on such a great forum.

By the way, the previous owner tells me that she had the actual ignition switch replaced about six months ago. She doesn't seem to remember precisely what was wrong at that time, except that she couldn't start the car. She told me that she did not experience the same smptom tha I am with the key turning freely. Also, I should mention that I've only owned this car for a little more than a month.

Is the tumber assembly turning freely? It sounds like the collar may not be completely screwed down to seat the tumbler.

John

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Certified Registered Nurse Anesthetist (CRNA)
2002 F250 powerstroke with Plantdrive WVO conversion
1983 300SD 190K miles ,sold
2006 E320 CDI

Did you recently take the cylinder out? It seems strange that after starting the car without the problem, the next time you try to start it that happens.

If I were you, first I would do what hangit suggested and see if you can tighten the collar - the thick black cylinder around the ignition cylinder. If that doesn't work, I would follow the instructions found in several posts in this forum about using the safety pin to take the cylinder out. Pull it out, make sure it looks like the pictures - good pics on dieselgiant's site - and put it back in.

When I have done it, if I don't get it in right it won't turn at all. I've never had it just spin around 360 degrees. But, it sounds like the tab that pops out is depressed and the collar isn't screwed down all the way, allowing it to spin. Good luck.

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1983 MB 300SD Turbo Diesel

Thanks for the responses. They also bring up a couple of questions. First, is the black collar threaded so that it tightens (and loosens) independently of the tumbler cylinder? I ask this because after reading about it in Haynes (the only manual I have) I just tried what JimZ suggested--that is, removing the collar/cylinder assembly by inserting a wire while the key is at the #1 position and unscrewing the assembly. Nothing seemed to want to turn. Being that I was following the instructions from Haynes, it was unclear to me whether I should be trying to unscew it by grasping the collar and turning, or turning the key counterclockwise while the wire was inserted.

I hate sounding so ignorant of this, but as I mentioned earlier I've only owned this car for a short time, and it's my first Mercedes after four old BMWs (three of which I still have).

Thanks again.

The black collar does turn independently of the cylinder, and yes, you unscrew the black collar, but at some point the cylinder will come out with it. If it doesn't turn, you don't have the safety pin at the right spot. That really is the trickiest part. Again, look at the pics on dieselgiant.com. His tutorial was most helpful to me the first time I did this.

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1983 MB 300SD Turbo Diesel

Follow JimZ's advice and tune in to www.dieselgiant.com tutorial on ignition lock removal. The trickiest part for me was finding the notch for the paper clip. I found it was easier and sturdier to use a very small allen wrench (similar diameter as paper clip). Good luck.

John

__________________
Certified Registered Nurse Anesthetist (CRNA)
2002 F250 powerstroke with Plantdrive WVO conversion
1983 300SD 190K miles ,sold
2006 E320 CDI

OK, I finally got the cylinder out. It seems to be on the verge of falling apart--the outer cap-like disk (that has the key opening) seems to be trying to partially separate from the actual cylinder. The whole thing seems loose, and now when I insert the key I'm having trouble turning it. It only turns when I jiggle or vibrate the key. This makes me pretty wary of trying to reinstall the cylinder. I'm now guessing that the cylinder is the problem. I've found some old posts in this forum that recommend FastLane as a source of this part at a quite reasonable price. Assuming I'm on the right track, how can I get such a generic cylinder keyed to accept my current keys without spending the entire savings from the dealer's price?

Thanks.

As far as I know, the only way to get a VIN coded cylinder if from the dealer. They'll probably give you a free key, though.

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1983 MB 300SD Turbo Diesel

When you buy the cylinder it comes with the VIN Coded Key - you cannot buy just the cylinder (anymore)

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Just a thought here. I recently had to replace the electrical part of my ignition. I bought the part online as I have done with most of the parts I need new. I was surprised to see the electric part I ordered did not have the locking feature the stock part had. My guess here is, since the PO said a new ignition switch had been put in, perhaps they got a switch like I did. Once the electrical is pluged into the cylinder, you have no way of locking it in place. Perhaps the electrical on your ignition has merely unplugged.

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I'm sorry I haven't updated this thread--I finally got the lock cylinder out, and found that the case was just about falling apart. It was easy to see how the key could continue to turn 360 degrees. I ordered a new generic (not keyed to the original ignition and door key) key online which arrived last night. I'm going to install it today, and I will update this thread later with a report of my results.

Sorry about my last posting (I'm trying to hurry, and forgot aboout the haste makes waste rule of thumb). I ordered and received a new CYLINDER which came with two keys, not just a generic key.

Thanks.

So, I went ahead and attempted to install the new tumbler cylinder according to the instructions found in DieselGiant's ignition lock repair tutorial. Everything seemed to go OK, except that once the cylinder and collar were tightened, the key would not turn. I disassembled it and tried again (actually several times) with no luck. It felt as though something was grabbing the cylinder, so I backed off slightly from completely tightening it and the key turned, but only enough to get the switch to where the dash lights illuminate, except for the glow plug warm-up indicator. It also won't turn enough to engage the starter (duh!).

I'm wondering if, as I posted early in this thread, the allignment of the actual switch was thrown off when the tumbler cylinder rotated 360 degrees (and more) in each direction. Is there any way I can adjust/rotate the switch and determine that it alligns correctly with the tumbler cylinder? In general, I don't know what to try next.

Thanks for any help that can be provided.

P.S. I took a few relatively clear photos with the tumbler removed to showthe position of the switch, but have had trouble posting them. I would be more than happy to email them to anyone who may find them useful.

post the pics to www.photobucket.com and click on the img link, then paste the text in the message window here... simple as pie.

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