Ignition key does not work all the time - PeachParts Mercedes-Benz Forum

admanles · #1 11-10-2004, 11:31 AM

Hi all, new to the forum, but from what I can see... it's a great one. I just inherited a 1980 300sd. The problem is in trying to start the car. I'm able to turn the key maybe a quarter turn in the ignition, I think right before the glow plug light would come on and it sticks, like there is something metal blocking the key from turning from that point on. I'll jiggle the key back and forth, move the steering wheel, remove the key a few times, say a few choice words, and eventually with a "click" the key would turn, and I'm able to start the car... It'll start fine a few times after that,... then it will happen again. It does it with both keys. Any ideas anyone as to what it might be? The only other problems so far, is the tach not working, which I remember a thread about that here somewhere, the left rear passanger lock not locking automatically (another thread I found) and the car being gutless, which from another thread might be a vacuum hose from/to the turbo? got to re-read that one... but you guys are great, lots of useful information. I'm hoping you can point me in the right direction on this ignition thing.

Thanks in advance

Les

#2 11-10-2004, 11:39 AM

You want to buy a replacement ignition tumbler from a dealer and either have it installed or install it yourself. Yours is worn out, and I'm told that if it becomes so worn out that your key gets stuck in there or it won't turn at all anymore, it has to be drilled out, which is a pain in the you know where. You'll need the car's title or registration as well as your drivers' license to order this part, if your dealer is like my dealer.

JamesStein · #3 11-10-2004, 12:09 PM

Before you buy the tumbler I would remove the one you have. My wifes 300D had a similar problem and it was not the tumbler but part of the ignition assembly.

Take a look at this page I am working on..

http://garnet.acns.fsu.edu/~jjs5772/W123

SD Blue · #4 11-10-2004, 01:01 PM

Before you start tearing things apart, have you tried lubrication?

Be sure and use only lock/key lube only. I have been told that anything else may cause even more problems internally. Maybe even resulting in the ignition needing drilled $$$.

whunter · #5 11-10-2004, 01:11 PM

If not, take it to the Stealership NOW.

When it stops working the repair time and cost will be higher.

Is this your only car?
DIY is cheaper on money, but will take more of your time.

JamesStein · #6 11-10-2004, 01:45 PM

I agree with whunter. If you don't feel comfortable working on it yourself take it in to get looked at now. If it seizes it gets very expensive.

I would seriously think about removing the tumbler, its easy to do, and check to see if its binding in any way at all. I would do that before I even thought about ordering a new one. Lubricating the tumbler with a graphite powder is a good idea. But I don't think it will help your situation. It really sounds like you have a failure in the internal mechanism of the assembly.