Key plunger/tumbler/pin cannot reach deep enough in ignition switch to start.

[steve92]

I could not find a topic that states exactly the issue I have. Allthough I found a very good description on how the ignition switch works:

"Inserting the key pushes a plunger on the key tumbler which pushes in a pin on the ignition switch electrical part, on the left side of steering column,

When this pin is depressed, after counseling, it connects terminal 30 to terminal S on the ignition switch."

It seems that the the key does push the tumbler as far as it could ever go into the ignition switch... I tried to pull the tumbler gently with pliers to see if there is any slack as if the tumbler didn't push out all the way.
(The tumbler can be seen in one of attached images, on the steering column, where the ignition switch electric thingy was)

When everything is put together as it should be, turning the key will power on everything but won't start.


I tried these steps and my conclusion is that the ignition switch electric part is not broken from my experience.

1. I removed the ignition switch electrical part from the steering column
2. left the key into the ignition switch key cylinder
3. connected the ignition switch electric thing back to the wire harness and left it hanging (holding in my hand in image)
4. turned that ignition switch electric thing with a screwdriver, pushing the pin in it all the way down with a flathead screwdriver

And it works! The ignition switch electrical part does work perfectly with a screwdriver and the car starts every time. But not the way it's supposed to, by turning the key.
If you press the key really hard into the key cylinder and then turn it, meaby you'll succeed in starting the car once in 3-5 tries.


Now for the question!

Is this a case of a bad ignition switch electric thingy or is this a bad key tumbler or plunger or the actual key cylinder itself?? Each part is around 100€ and the ignition switch electric thingy does seem to work however only with a screwdriver... Replacing everything in this system would cost like 500€. And I don't even know how difficult it even is trying to replace the tumbler (The thing that presses the pin on that ignition switch electric box thingy) I suppose for antitheft reasons it's not disassemblable.

[scot850]

The ignition key tumbler is removable, but it requires either using a Dremel and cutting a slot in the safety/security bolt heads to remove them or cutting the heads off. You will need new ones for re-install.

There is a locking part that can break off in the assembly but as it has not happened to me (yet) I can't advise.

What can also happen with a worn key is it can no longer push the tumbler blades out far enough to let this work.

I have only had issues with the electrical portion so far (thankfully). What happens when you put the key in and turn it with the electrical position not attached? Does the part that fits in the electrical portion rotate?

This thread may help, but not sure if it is the same issue:

viewtopic.php?f=1&t=67531&hilit=Ignition+key+tumbler

I don't like using penetrating oil in locks as they can make things worse, BUT, if all else fails, maybe using penetrating oil with a nozzle tube into the ignition key slot may be worth a try. Once it has a chance to dry out, at some point try some graphite dust (locksmiths use it) to re-lube the lock mechanism.

Neil.