99 e300 here is what is happening:
sometimes (50% of the time I am driving the car I hear a clicking noise coming from behind the dash near the ignition switch. If I lift the key the or move it some the clicking will stop. When the clicking sound is taking place I can feel the key move. The clicking sound is not as loud as the sound that takes place when you first insert the ignition key but still pretty pronounced. Also I have noticed the horn or sunroof does not work unless I lift the key slightly when driving.

I am down to 1 key. The other key stopped working (stop being recognized by the ignition switch) about a year ago.

This is probably a solution for the dealer to fix but my fear is potentially waisting $300.00 because I am sure that is the first suggestion will be that I need a new key. If that fixes the problem great but if it doesn't, I am sure a super-expensive new ignition switch will require an entirely different set of keys as well (another $300 for each key)

Any suggestions on how to proceed?

I'm pretty sure the dealer is the only one that can help out with the key issue.

__________________
Jim

Have you replaced the battery in the key fob that stopped working, to see if that was why it quit working?

$300.00 to keep the car driveable doesn't seem to be that great a cost in the grand scheme of owning and driving that car. I'd drop amount of money in a minute, were my car's fob not working to keep driveable.

You do know that there is a blank looking, lightweight chipped key fob used for the valet on that model car don't you? That would seem to be a better everyday ignition activator than the heavy, battery-packed key fob anyway.

__________________
'06 E320 CDI
'17 Corvette Stingray Vert

Also clean the infrared port on the key and tumbler.

Thanks guys,
I will polish the current key that is working as well as the older key which doesn't seem to be recognized by the ignition switch.

Also batteries are all fresh

Skid row, as I stated $300.00 is ok if that fixes it but if not, I am looking at two more new keys to fit another ignition switch, so the math looks like this:

first key try total loss $300+ new ignition switch (probably $500.00) + 2 more new keys to work on the new ignition switch ($600)=$1400.00 worth of trial and error and the car wont go any faster after the new key is installed!

I plan on taking the car to the dealership later this week and will follow up as this progresses.

The battery in the key only operates the door locks and the lil red indicator light on the key fob. Nothing more......

Try using two fingers on the chrome ign bezel and tighten it up if its loose.

Also, lose all the extra keys and beer bottle openners on your key chain. All that extra weight is not your key's friend.

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

You didn't say whether you had the valet key I described above, so I am going to assume it was news to you. You might enquire from the dealer about a replacement. It's the creme-de-la-creme in light weight.

If you bought the car used, I could easily see that the key went missing, or even unoticed by you and, or the previous owner.

If memory serves, having bought mine new in 1999 - the valet ignition/door key fob was placed in the zipper bag containing the car's owners manual. Check in there - for this valet fob.

If money's tight, the lightweight valet fob (following>) will work indefinitely.

Here's mine in the following pic. (finger pointing to it) next to the much bigger and heavier electronic key fob:

Attached Thumbnails

 

Here's what the key fob's integrated driver's door pass key looks like, which you remove from the plastic fob to gain access into the car, and to lock the car.

Attached Thumbnails

 

great idea, I will try to tighten up the bezel.

Thanks Skid Row, I actually did receive that key plus a "fake key" that houses the metal door key. Now if I could only find that bugger!