85 300D: Bad Ignition Cylinder?

[rbc]

Hi,

I have searched and think I need a new ignition cylinder. But am curious if the old one can be saved.

Basically the car acts as if the ignition is engaged, but will not un-engage. In other words, the power lights are all on, but I cannot get ignition. When I take the key out, the power lights stay on. When I try to go the extra turn to engage the starter, it ticks behind the stereo (kind of like when you try to start the car in drive) but nothing happens. I was able to (once) get the ignition to reset (power lights went out and seatbelt buzz came on), but the starter would not engage when I turned the key.

The car was in the shop TODAY, and I am concerned it stuck and they sprayed lube in there. That's a no-no.

Thoughts? Pull the cylinder and soak? Just bite the bullet and buy new one? I spent ALOT of time tinkering with it to get it to reset and fire the starter. Almost lost me marbles.

[rbc]

More information ...

So I pulled the tumbler. It rotates relatively freely (a little hitchy, could use a cleaning), but IF the role of the tumbler is just to allow a turning of the key -- and simply engaging the ignition switch with those 2 teeth -- then it seems to work fine.

So now I have to suspect the ignition switch? As stated, the key would turn all the way, engage the power of the car, but not engage the starter. When the key was turned to off, the power stayed on, and it would not reset.

Thoughts? I am searchin!

It may be the switch, I had to replace mine once. It's a bit of a PITA to remove, but I wold probably pull it out and check. It might only be the electical portion of the switch.

[rbc]

Thanks Craig. PITA because I have to take off the cluster right? If so, anyone have a link to getting that done? I was praying it's not the switch. Is it recommended to just replace the electrical part on the end? Or the whole 3-part ignition housing?

I've done it by just pushing the cluster partially out of the way without disconnecting anything. You can get to it from under the dash and loosen the "clamp" that holds it to the steering column and pressing a little locking pin out of the way. It's pretty tight, but you should be able to get the whole unit removed in about 20-30 minutes the first time. After you get it out, it should be obvious what's broken.

[rbc]

Cool. Thanks. One last question (as if) ...

... could the symptoms I describe (electrical power staying on while key is off and out, cannot engage starter) come from a vacuum problem with one or both of those two brown lines? I just got the car back from a buddy for engine mounts and I am wondering if connecting the vac lines wrong could mess things up at the ignition? That said, this problem was gradual. First it would not start every blue moon -- turn key back and reset and not problem. Now it's just not starting. Key does not seem to engage stages like normal. Thanks for the help.

[rbc]

Ok, instrument panel out. U clamp removed. Now,do I need to put the tumbler back in and re-engage the key to get the ignition unit off the steering column? It seems there is a pin designed to theft deter, but from reading other posts but I cant figure out how to deal with it. In other words, will a re-engaged key allow me to simply push the pin in? And where is this pin?

Can you see the little round "button" on the "shaft" in the photo?

http://catalog.peachparts.com/ShopByVehicle.epc?q=&yearid=1982%40%401982&makeid=63%40%40MERCEDES+BENZ%40%40X&modelid=6190%3AMBC%7C1504%3AED%7C10000135%40%40300D&keyword=ignition&subcatid=P:241651@@Ignition+Lock+Housing&mode=PA

You need to press that button in to allow the ignition to be removed. I believe that you can manually push that button (pin) if it's in an unlocked position. You should be able to turn the switch with a screwdriver, if necessary, without installing the lock cylinder.